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.