Computer folder keeps appearing after startup!

Run msconfig and disable those autoload programs. At least temporary and reboot. Still same problem?
don't forget to run msconfig again and select "boot normally"

pegs said:

No, that didn't help, Kaktus. Windows Explorer still opened up automatically on boot.

All user accounts have this problem? Create a fresh new account and test.
Also try Troubleshoot Application Conflicts by Performing a Clean Startup
don't forget to do step three when finished testing


Click Start, in the search box, type Regedit.

Navigate To > HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

In panel on the right, change value of "Userinit" to : C:\WINDOWS\system32\userinit.exe
Was it already?

pegs said:

No, that didn't help, Kaktus. Windows Explorer still opened up automatically on boot.

Also if booting in "safe mode"?

Maybe this is a job well suited for Autoruns for Windows.