Tech Tip: Enable Concurrent Desktop Sessions in Windows

By on January 6, 2012, 12:46 AM

Professional and Ultimate editions of Windows come with a built in Remote Desktop (RDP) feature that allows you to access your machine remotely while away from home or the office. Unfortunately, it is limited by default to one concurrent user per session, this is not a technical limitation but rather a licensing one.

Case in point, Remote Desktop in server editions of Windows by default supports two concurrent connections to remotely troubleshoot or administer a computer. However, there are a few reasons why concurrent sessions would come in handy for power users not necessarily running a server. For example, if you have a dedicated Media Center PC running in the living room, you'll be able to remotely access all files on the machine without interrupting the person watching TV.

Or if you are sharing a computer with other users, concurrent Remote Desktop sessions will allow more than one person use that system under a different or even the same user account, without kicking each other off. By patching a file called termsrv.dll, located in %SystemRoot%System32, this is possible in all editions of Windows 7, Windows Vista and Windows XP.

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User Comments: 50

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Guest said:

I hope the author realizes that by enabling this "hack" he's actually breaching his Windows license agreement, and thus creating an illegal copy/installation of Windows on his machine. Better than that, he's practically recommends doing the same to others.

Guest said:

I have a couple of PCs, the main one I'm using now runs Windows 7 Ultimate, and downstairs

a PC running Windows XP Media Centre Edition ... so I expected there to be no problems.

<=> I ran the patch as Administrator on the WXP MCE machine, and rebooted as prompted.

<=> After waiting for reboot cycle to be completed I logged on to that machine as normal.

<=> Came upstairs to this W7Ult machine, and RDC'd into the WXP MCE machine.

<=> Went back downstairs to find it had dropped back to the WXP logon screen.

<=> Logged back on to the WXP MCE PC and returned upstairs to this PC.

<=> W7Ult says "Remote Desktop session has ended." . . .

So basically ... the patch doesn't work.

Darth Shiv Darth Shiv said:

"For example, if you have a dedicated Media Center PC running in the living room, you'll be able to remotely access all files on the machine without interrupting the person watching TV."

Exactly how I use it with this hack.

"I hope the author realizes that by enabling this "hack" he's actually breaching his Windows license agreement, and thus creating an illegal copy/installation of Windows on his machine. Better than that, he's practically recommends doing the same to others"

And I hope you realise introducing ridiculous artificial restrictions and draconian licensing is why people hate the record and movie industries. Microsoft has done well to embrace the open hardware platform and allow great flexibility in their software platform.

Guest said:

Ask Steve Gibson from Gibson Research if he would ever recommend 'patching' a critical Windows DLL file. Not a good idea at all from a security perspective I'm sure.

Staff
Per Hansson Per Hansson, TS Server Guru, said:

Is it possible to increase the limit on Windows Server editions from the normal maximum of 2 concurrent users without a terminal server license too?

SeiveD said:

I'd like to know what kind of keyboard they have on the front page for this article.

Burty117 Burty117, TechSpot Chancellor, said:

that is simply the coolest keyboard I've ever seen!

Guest said:

The keyboard looks to be an Optimus Maximus, they are ~$2k IIRC

SeiveD said:

Ah, Indeed it is. I'll wait until I'm filthy rich to buy one, then.

Guest said:

Great tip. I've been using this for the last several versions of Windows thanks to these guys guide - http://www.missingremote.com/guide/how-enable-concurrent-ses
ions-windows-7-service-pack-1-rtm

Guest said:

Been doing this since the Windows XP days, should be a default feature of the Pro / Ultimate version of Windows.

jobeard jobeard, TS Ambassador, said:

I hope the author realizes that by enabling this "hack" he's actually breaching his Windows license agreement, and thus creating an illegal copy/installation of Windows on his machine. Better than that, he's practically recommends doing the same to others.
the article plainly states

"This is not a technical limitation but rather a licensing one." so your comment is fact; this is hack that breaks the terms of the EULA.

Guest said:

How can we be certain that the author of the patch has not installed his own backdoor, now allowing him full access to all patched systems?

Staff
Rick Rick, TechSpot Staff, said:

This patch *must* modify the termserv DLL by either reverse engineering it or replacing it with Windows Server version. Either method most certainly breaks intellectual property / copyright laws.

Truth be told, the responsibility falls upon the developer, but I was surprised to see this here.

Is it possible to increase the limit on Windows Server editions from the normal maximum of 2 concurrent users without a terminal server license too?

I have not tried this, but I read by using the termsrv.dll from Windows Server Enterprise (not Standard or Business edition... Data Center would probably work too) and modifying the policy options under Computer Configuration > Administrative Templates > Windows Components > Remote Desktop/ Terminal services.

If you're running Windows home and don't have gpedit, there is a registry equivalent, but I do not remember where to find it.

KBadaloni said:

Does this mean it will work on Windows Server 2003?

Staff
Julio Franco Julio Franco, TechSpot Editor, said:

As noted on the article, Windows Server has this feature enabled by default (with a limitation in terms of number of users). What this hack accomplishes is to enable the feature in client versions of Windows XP, Vista, and 7.

otester said:

Microsoft supports SOPA, therefore everyone should be boycotting and sharing their stuff.

Also US law doesn't govern the globe.

Guest said:

If you need to share the desktop with someone why not just use Remote Assistance? Once you get the user's permission you can control/share their desktop legally.

Guest said:

Teamviewer or VNC anyone?

yukka, TechSpot Paladin, said:

This would work brilliantly at work if it didn't conflict with the EULA. To be able to log in remotely to a local admin desktop session to carry out tasks while the user is still logged in to the machine would save us so much money in wasted time as our users have a tendency to leave themselves logged in with the screen locked. To be able to still remote to the machine.. dream!

Still, can't use it. Breaks licencing. Bummer..

yukka, TechSpot Paladin, said:

Guest said:

If you need to share the desktop with someone why not just use Remote Assistance? Once you get the user's permission you can control/share their desktop legally.

Remote assistance shares the desktop with the user. Being able to actually log in as admin means you could explore the setup of the machine as if logged in while the user still continues to work. Remote assistance means they have to stop what they are doing while you use their desktop. It also doesn't help if they have left the machine logged on and screen locked. You can't do anything without kicking them off.

I know a number of mmc snapins work remotely but once you remote desktop to a machine then you can do absolutely anything which in some cases would be just awesome.

Guest said:

I would love for all the sticklers to actually point out WHERE you are violating licensing. You're editing a DLL, not avoiding activation. By your same logic, everyone who has patched their UXTheme.dll to use custom windows themes are also pirates.

Staff
Rick Rick, TechSpot Staff, said:

I would love for all the sticklers to actually point out WHERE you are violating licensing.

First, the concurrent use of RDP is expressly prohibited:

NetMeeting/Remote Assistance/Remote Desktop Features. The Product contains NetMeeting, Remote Assistance, and Remote Desktop technologies that enable the Product or other applications installed on the Workstation Computer to be used remotely between two or more computers, even if the Product or application is installed on only one Workstation Computer. You may use NetMeeting, Remote Assistance, and Remote Desktop with all Microsoft products; provided however, use of these technologies with certain Microsoft products may require an additional license. For Microsoft and non- Microsoft products, you should consult the license agreement accompanying the applicable product or contact the applicable licensor to determine whether use of NetMeeting, Remote Assistance, or Remote Desktop is permitted without an additional license.

You're editing a DLL, not avoiding activation. By your same logic, everyone who has patched their UXTheme.dll to use custom windows themes are also pirates.

Secondly, that DLL "patch" required reverse engineering OR distribution of the original DLL (which is not yours to distribute, it is Microsoft's IP). It isn't some bit of novel programming and a registry change that allows Windows to have concurrent sessions of RDP, rather, it uses Microsoft's own technology, protocols etc...

LIMITATION ON REVERSE ENGINEERING, DECOMPILATION, AND DISASSEMBLY. You may not reverse engineer, decompile, or disassemble the Product, except and only to the extent that it is expressly permitted by applicable law notwithstanding this limitation.

Guest said:

Microsoft licensing isn't designed to be fair, it's designed to extract the maximum amount of profit. Which is why any power-user worth his salt will already know about the patcher and have made up their own minds to simply accept the small possibility of any consequences of breaching the EULA.

Guest said:

I agree with an earlier post in this thread saying that I cannot get this to work. I get the "patch success" message, and restart, but when I am watching TV via Media Center, and then try to RDP from a laptop, it kicks me off from the PC and locks it.

Does this patch really work, and if so, what are we doing wrong?

Thanks

Jeffkw said:

"...in all editions of Windows 7, Windows Vista and Windows XP..."

Does that include the Home editions, which do not normally support Remote Desktop?

Guest said:

When logging on concurrently, you need to log in using a different account than the one that is currently logged on, otherwise it will just take over the current session

Guest said:

for those who cant get this to work, check that the Windows Firewall service is enabled and running, the firewall itself does not need to be enabled, just the service running

Guest said:

Who cares?

It is useful for Media Center and to share pc

Buckshot420 Buckshot420 said:

I'd like to know what kind of keyboard they have on the front page for this article.

Something like this.

[link]

spydercanopus spydercanopus said:

Will this affect ability to install future updates?

Staff
Rick Rick, TechSpot Staff, said:

Jeffkw said:

"...in all editions of Windows 7, Windows Vista and Windows XP..."

Does that include the Home editions, which do not normally support Remote Desktop?

All Home editions support remote desktop.

Start > Run > Mstsc.exe

Guest said:

I really can't believe that a Tech site is encouraging a Hack.

I can't believe users are so naive (especially those on site like this) that a modified core DLL, that comes from some random blogspot site couldn't possibly contain a backdoor.

If you really need to Update your Windows Media Center so deperately that you can't take it offline for a while maybe you need to reevaluate your priorities.

Jeffkw said:

Rick said:

All Home editions support remote desktop.

Start > Run > Mstsc.exe

As clients.

I guess I should specify. Does this hack enable Remote Desktop server on Home Editions?

Guest said:

At first I thought this patch wasn't working on my Win7 Ultimate PC, but then I realized that it does, in fact, do part of what it advertises. I can successfully log in remotely and leave my console connection active, but only if I do so as a different user. If I try to connect as the same user, or if I attempt to connect multiple remote connections as the same user, only one connection for each user will survive. The REG files included in the zip file suggest that they will remove this limitation, but on Win7, at least, they don't.

So, if you are happy being able to make multiple concurrent connections to your PC as different users, then this patch may be for you. If instead, you need to log in as the same user more than once concurrently, look elsewhere. (Windows Server?)

Guest said:

Wonderful concern over licensing. Attacking SOPA or supporting it is not the issue.

I am a consumer, I will buy what will do for me what I need it to do, I want it to be legal and to save me money. I would like to have a single or dual PC home server that runs Windows 8. My ideal configuration would allow my PC system to run on multiple devices simultanously so I do not need as much HARDWARe, this maximizing the use of hydro and reducing maintenance costs.

I expect that MS will licence its software on Displays (TVs) in the next round of licencing, but I prefer maintaing a high speed computer system that can serve as a a hub to a Whole Home Entertainment and Communication system.

Is that too much to ask?

Guest said:

You folks would need to get a grasp of how Terminal Services/Remote Desktop works on Server2003/2008 to see how this is supposed to be used.

Do some research, look up thin clients, etc. etc. This is a hack, yes, but it is a Server 2003/2008 hack and Terminal Services is a services on those servers that allows many people to connect to one machine. Why?

Say you hire a CPA, rather than them coming to your office, you could create an account on your server (called CPA) and email them the RDP client (which can also be downloaded as well, even for Mac)

When they log onto your Terminal Server they can have a uniformed experience to your resources. Mapped drives, Office, Adobe, Quickbooks, etc. etc. When they are done or you need them gone, disable their account, they cannot get in.

RDP uses very high encryption.

Can be used in conjunction with a VPN but not necessary.

No need to mail someone a laptop or setup workstations for each person.

Updates and application versions are all universally the same and deployed on the system.

Group policies can limit access.

You can lock down a terminal server to limit what users can do.

They can remote print to the internal company printer or their home.

With 3rd party programs like TSScan and RemoteScan they can scan as well with their client scanner.

As you can see the possibilities are endless, but most home users would never need this much flexibility.

shaft80 said:

tried it on an xp machine accessing from win7 and vista....didnt work

pjamme said:

My AV wouldn't alolow downloading. Called it a Crack.

Guest said:

Can always use a different operating system that doesn't have the same EULA limitations. problem solved, without feeling guilty about buggering your DLL files. That is probably the best work-around.

Guest said:

Excellent Good work. Does exactly what is says.

Guest said:

Just FYI:

After patching Termsrv.dll with the .exe file, YOU NEED TO REGISTER THE DLL! To do this run the corresponding .reg file for your OS (e.g. xp.reg for WinXP and vista.reg for WinVista).

Cheers!

Guest said:

I changed my Win 7 Enterprise SP1 64 bit to concurrent user by running the termsrv.dll. But now I want to restore it back to the original setting with single user RDP access. I have the termsrv.dll.backup but it would not allow me to do anything. I cannot restore to a previous date before I made the system concurrent, since it has been 6 months and cannot restore to that point with other updates made in between then and now. Can someone please help me remove the concurrent setting to the original single user RDP setting?

Thanks, Ashley G

isomorphismes isomorphismes said:

Despite not being very old, the mirror links to this .dll file now appear to be broken. They link to phishy-looking sites. (one Russian, one Chinese/Japanese/something, another just phishy)

Guest said:

Possible a coincidence, but after I applied the patch (which worked, by the way) I was unable to map to a drive on that computer from another computer. Is this a problem?

jobeard jobeard, TS Ambassador, said:

Been doing this since the Windows XP days, should be a default feature of the Pro / Ultimate version of Windows.

It is on Windows/7 - - even with cross-platform Mac accessing Windows

[ie no hack/patch required]

tipstir tipstir, TS Ambassador, said:

TCP.SYS get's backup then replaced with the one without the limiter which by default is 10. I've had these changes for years. Based on DIR-655 Router which could handle MCS of 200 the system would be set from 10 to 100. Base today on faster routers the system would go from 100 to 200. Most users could use setting of 50 instead. I only have one Windows 7 U-64-bit using the 200 setting. Another desktop running at 50. Considering running TCP Optimizer and running additional code name JASPER script I came up with will give you what Windows 8 gives you now TCP Global

Now that's only one part of the puzzle. Three is the TCP GLOBAL settings. Running a script could change that.

Windows 7 32/64-bit

Showing Prior Check the TCP/IP state PROCESS STARTED

Querying active state...

TCP Global Parameters

----------------------------------------------

Receive-Side Scaling State : enabled

Chimney Offload State : enabled

NetDMA State : enabled

Direct Cache Acess (DCA) : enabled

Receive Window Auto-Tuning Level : normal

Add-On Congestion Control Provider : ctcp

ECN Capability : disabled

RFC 1323 Timestamps : disabled

Press any key to continue . . .

Windows 8 Preview 32/64-bit

Windows 8

TCP Global Parameters

----------------------------------------------------

Receive-Side Scaling State : enabled

Chimney Offload State : disabled

NetDMA State : disabled

Direct Cache Access (DCA) : disabled

Receive Window Auto-Tuning Level : normal

Add-On Congestion Control Provider : none

ECN Capability : disabled

RFC 1323 Timestamps : disabled

Initial RTO : 3000

Receive Segment Coalescing State : disabled

-----------------------------------------------------

After on Windows 32/64-bit

TCP Global Parameters

----------------------------------------------------

Receive-Side Scaling State : enabled

Chimney Offload State : enabled

NetDMA State : enabled

Direct Cache Acess (DCA) : enabled

Receive Window Auto-Tuning Level : normal

Add-On Congestion Control Provider : ctcp ( experimental gives you a little more Mbps )

ECN Capability : disabled

RFC 1323 Timestamps : disabled

Initial RTO : 1000

Guest said:

Works fine!!

TY "a loottt", I was searching for this a "looonnngg" time!!

Congratulations!!

Guest said:

So, we should NOT make our lives easier because of a hack which WON'T make a difference for Microsoft neither financially nor about intellectual property. Yeah that's really reasonable...

Not only we SHOULD apply this hack, but Microsoft should explain itself for blocking our purchased OS from doing stuff that IT IS capable of.

drk2k drk2k said:

This work only with local user account not in a domain with AD users.... no good!!

and yes. it break the license agreement!!

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