[gsandan]

If I toggle UAC on after Vista asks me to reboot to apply the changes, I get a black screen with only the mouse. I can do a CTRL + ALT + DEL but, Vista won't let me into the task manager to execute EXPLORER.EXE. WIN + R does not work either so, I can't start EXPLORER.EXE.

Anybody have any ideas?

[gosh]

Well vista uses a driver for UAC, so, enable boot logging and see what the last service was loaded. You could try sfc /scannow (if that still exists in vista) or repair vista

-gosh

[cluberti]

It's actually switching the desktop window to the session 0 window (to allow you to see the UAC prompt), and a good test is to boot into safe mode (VGA) boot, and see if it does the same thing. If so, then sfc /scannow is definitely a good move. If it doesn't, however, you've got a driver (video) problem...

[gsandan]

I can boot into safe mode without any problems.

I tried the low resolution boot and still nothing.

Also did a sfc /scannow, and still nothing.

Any other ideas? (Does UAC depend on a service)