For the last year or so my laptop has taken up dropping the internet connection, working with either a wireless or wired connection to the router, about every 12-24 or so hours (it seems to vary), and no matter what I do, my laptop will not renew the IP address unless I restart my computer. It still communicates with the router/home network (I can still use the printer on our network) but refuses to connect to the internet without restarting the computer.

I have checked that all my internet connections are set to automatic and have tried going into the command prompt and releasing/renewing the ip address, but this does not work. It will not renew the ip address. I have to restart the computer every time, and occasionally I have to restart the computer two or three times before it will pick up an ip address. All of the other computers on the network work fine, wireless or wired. Even when our other wireless computer looses the router signal, it will renew its ip address with no problem. Only my laptop is doing this. Any other suggestions other than setting the network connections to automatic and/or using command prompt to renew the ip address?

What router or routers are you connecting too? Just to confirm this happens to you if your using a wireless or wired connection? Does your network administrator at your work know your using your laptop? Does this only occur at work?

Just thinking out loud until more info is given:
It sounds like the other computers on your network connect and disconnect often, however your laptop is the only computer having trouble reconnecting. The router may be setup to assign identification numbers (for lack of better word) to each computer that connects to it. Duplicates assigned numbers with other computers can cause this. But if your laptop is the only one experiencing other problems then I doubt it.

It happens with any router, anywhere, wired, or wireless connections. I'm unemployed right now (so I have no network admin.), but I have tested my computer recently at my mother's house when I was on vacation recently. My mother had an old Netgear router (not a wireless router), and I use a Linksys (wireless) at home. It seems my computer is at fault, not the router settings. I have experienced issues before with a router assigning the same number to two computers (when one computer went to sleep or something like that), but that is not the issue in this case.

The ISP end is performing a Release/Renew cycle frequently and apparently the router and other systems are processing it correctly.
If only YOUR system has problems with Release/Renew (btw: you can test this for yourself [*] ),
then I would seek to update your NIC and WiFi drivers.

[*] To test your ability to Renew a connection, logon as an admin and get a command prompt (run->cmd) and do this sequence

1. ipconfig /all
2. ipconfig /release
   and wait 30 seconds
3. ipconfig /renew
   and wait 30 seconds
4. ipconfig /all

#1 will give you an example to compare to #4.
If you wish to see the progress, you can use the ipconfig /all between each step

For XP Only!

Under My Network Places

Set up a home or small office network
Make sure your workgroup matches what's in there
and continue to run..

Next do the following...

click on start
click on run
type: cmd

type: ipconfig /flushdns

******************************************
If you use ipconfig /flushdns and get an error:

Could not flush the DNS Resolver Cache: Function failed during execution.

This means

DNS client service is not running

To Fix:

click on start
click on run
type: cmd

Type the following as you see it:

REG ADD HKLM\SYSTEM\CurrentControlSet\Services\Dnscache /V Start /T REG_DWORD /F /D 2

Press enter and wait for the message that said OK

Exit out an then exit out of Windows..
After the reboot login to Windows..

click on start
click on run
type: cmd

type: ipconfig /flushdns

*********************************************************
continue...

type: netstat -r
type: netsh interface ip delete arpcache

Now go to your Network Connections
Right click on your LAN or WLAN
Click on Properties
Click on Internet TCP/IP
Click on Advance

Default Gateway should have your DG (router)
If not put the IP in there and leave the Metric alone.
Click on the Wins tab
Change Default NetBIOS
To Enable NetBIOS over TCP/IP

Click apply or okay

Now...

click on start
click on run
type: services.msc

Make sure.. Computer Browsing is Enable and Started (auto)
Make sure... Network Connections is Enabled and Started (auto)

If you want your Router to show up under My Network Places under XP like it does Under Vista & 7

You need to make sure SSDP is enabled and started (auto)
You need to make sure UPnP is enabled and started (auto)

In your router turn on UPnP (some of you say it slows down your connections, but I don't see that happening..

Now under My Network Places there is:

Show UPnP Devices click on that.. If you get an error, then you need to rebuild the dbase.

Fix is here:

Click on start
click on run
type: esentutl /p %windir%\security\database\secedit.sdb

Source: My Bog

wow - - lots of extraneous work there buddy. Not once have I found that to be necessary,
and UPnP certainly is not necessary - - but you and I seem to argue this point over and over.

imo, Techspot ought to be solving the original posters problems without inducing extra work that is not a part of the solution.

I'll just bow out and let you lead the parade ...

I know you always make this comment about the UPnP. I've been using for some years now without issues on XP box. The above is everything in one shot. But this gives the user who has home router and anything attached to this router will also appear in Network Places. All APs, CB, PS etc. You can invoke the Router Web Admin from My Network Places. Just to let you know if your router and you are sync-up or not on XP. The feature can be disabled at any time. On my two re-build DELL Latitude wireless laptop they both have this feature enabled. My PS (printer server) is directly link to them) along with the router shows up in Network Places.

But don't bow out though stick around!

dependencies are meaningful

I'll say it this way

• Universal Plug and Play Device Host
  depends upon: SSDPSRV HTTP
  

  • SSDP Discovery Service
    depends upon HTTP
• TCP/IP Protocol Driver
  depends upon: IPSec

  • IPSec driver
  • RPC
  • TCP/IP
• Network Connections
  depends upon RPC
  and W.Firewall depends upon Network Connections &
  the Firewall also depends upon RPC

From that mapping, the likely candidates for connectivity issues would be
TCP, RPC, the IPSec driver and the Windows Firewall.

*After* connectivity is available, the any other stuff just adds utility but does not alter the ability to connect, but that's only my opinon - - -

ipconfig/all gives me:

Dhcp Enabled. . . : yes
Autoconfiguration Enabled. . . : yes
IP Address . . .: (good ip address)
...etc, looks fine...

So I did ipconfig/release, and ipconfig/renew, and I get:

"An error occurred while renewing interface Local Area Connection : unable to contact your DHCP server. Request has timed out."

then when I do ipconfig/all, it gives me:

Dhcp Enabled. . . : yes
Autoconfiguration Enabled... : yes
Autoconfiguration IP Address. . .:169.254.5.72 (which is beyond my comprehension - this is nothing like my IP address.)

I will add that I use Comodo, not Windows firewall. Also, doing ipconfig/flushdns does not cause any errors.

I will try this suggestion next I guess:

continue...

type: netstat -r
type: netsh interface ip delete arpcache

Now go to your Network Connections
Right click on your LAN or WLAN
Click on Properties
Click on Internet TCP/IP
Click on Advance

Default Gateway should have your DG (router)
If not put the IP in there and leave the Metric alone.
Click on the Wins tab
Change Default NetBIOS
To Enable NetBIOS over TCP/IP

Click apply or okay

Now...

click on start
click on run
type: services.msc

Make sure.. Computer Browsing is Enable and Started (auto)
Make sure... Network Connections is Enabled and Started (auto)

this is THE issue and cause of the :169.254.5.72 address

in your firewall, set this rule and move it to the top of the list

allow tcp/udp in/out src=any dest=any port=67,68

Done. Will see if this works. Thanks!

Preliminary testing seems to show that was the problem/solution. I never, ever would have figured that out! Thank you so much!

your welcome.

some firewalls are 'very strict' in the rule set and others make bold assumptions and
allow some trivia (like DHCP and DNS) to escape control.

btw: if you get errors like Server Not Found or Timeouts in your browser,

then copy the DHCP rule and change the PORT to 53; move to the top

I would add this to a rule in the main router. Some router brands I've been testing causes these issues and some don't!

something like a Cisco Commercial router might need that,

but Comodo & Sunbelt Firewalls need these rules for themselves and the OP has Comodo

Comodo blocks way to much of the wrong LAN and WAN settings. Best to use the OS Firewall instead. Good points you have shown the OP. Handshake for you!

Personally, I like Comodo and a very strict rule set - - Makes me responsible for my actions
and the results.

I commented to the Comodo Forum re using profiles to solve laptop issues;
eg: Home, Work, Hotspots all needing different settings - -
Microsoft must have been reading too, as the Win/7 firewall now delivers that functionality.

If&when I get to Win/7, for the first time I will opt for the MS Firewall - - does a good job imo.

I've used Comodo Firewall many times, and ran into issues where the FW was just blocking the wrong systems on the network where they needed to be accepted. Rules can be edited but there was times it just keep on repeating. My goal is to make the network streamline. I do a lot of RDP here. Those connections need to be very quick and operation process can't have any delays.

I've chosen both OS firewalls XP Pro SP3 and Windows 7 32/64 bit H | U firewalls with MSE 32/64 bit without issues. The UAC is a bonus. Still the latest router I am using has two different hardware NAT and support for hacker shield.

MS FW for me though in the end on the client side and server side DHCP hardware FW. Not to get off the topic but have you ever use Netcps on your Cisco Catalyst switches to test their performance from Server to Client side?

Comodo is impressive at first but became annoying in the long run. Im on the OS bandwagon now.