Vista goes to a black screen with a cursor after logon password is entered

[pyromaster114]

So my friend says his computer goes to a black screen and sits there when he logs in, and supposedly it sits there for about 1.5 minutes and then goes into windows.

I though "That's odd, must just be a bunch of crap running in the background..."

So I get there and I disable every start-up process under the sun that i can think of, and the thing still does it.
So I got to thinking: Well I'll disable user access control so when I hit CTRL ALT DEL it'll start the task manager as admin by default, and I'll look at what it's doing on that black screen for so long.

Well apparently that's what's actually causing the problem... or so it would seem.
I don't know why that would be. I disable it and the problem just goes away... like magic.

It's running Windows Vista Home Premium.
It's some HP model, about a year old or so.

He's pretty satisfied with the solution, but I want to know what caused it, on account of it could be a security risk.

I've run Malwarebytes, and he was using Avast Antivirus, and neither reported any problems... the computer runs fine with and without UAC after it finally boots up.

 

[Ultiweap]

There are multiple possiblities for that.

1. It may be due Vista Updates just got updated and configuring.
2. A new program got install and was not configured well.
3. Too much program on startup making conflict on startup.
4. UAC blocking a program to run on startup.

Those are the most probable.

 

[pyromaster114]

Vista didn't just update, and I restarted about 30 times, let it sit on for 3 hours, etc., nothing really made any difference.
A lot of games that he had installed were removed, but the problem apparently pre-dates that.
Well from what I can tell, it's not a bunch of start-up processes because it literally only starts like 5 things (antivirus, video driver utility, and a few others).
I'm pretty sure UAC is blocking something windows thinks is necessary, and it's having to wait and see if it is allowed to start something, and finally gives up after about a minute or so.

I think this may be another problem like I encountered with the file system permissions on my computer once, and it turned out Vista's system somehow wasn't listed as admin or something like it should have been.

Later if I can get at the thing I'll check the permissions and groups against mine and another computer and I'll see if I can find anything.

 

[Ultiweap]

Try going to safe mode and check if it do the same.

Then when back on windows disable UAC completely and check what this give. If the problem this may be a problem with a Windows file maybe corrupted or missing.

Also another thing you may do is to make a complete defrag of all drives on the PC.