BleepingComputer.com: Vista Hangs At Startup... Please Help

I have a HP notebook working on Intel 2Ghz Duo, with 4 Gb of RAM and 2 harddrives of 160 Mb each running on Vista Ultimate 64-bits.
Got this notebook since a few months and all worked fine until yesterday. Windows Update told me there was a new update installed for which I
had to restart. After closing down windows the update installed, my computer restarted and all was fine. After finishing my work I closed the
laptop, which normally puts it in sleep-mode. When I later on opened the laptop again I got the login-screen, entered my password, the
computer waited a few moments, then I got a blue screen with a (long) message, which dissappeared very fast, the screen went black and that's it.

Problem is when I try to reboot, all I get is the BIOS startup screen, after that the green rolling bar of Windows (all normal upto now)
and after that a black screen with nothing but my mousepointer. No disk activity. No nothing. Safe mode won't work, I don't have a backup
to restore back to. Windows Vista Repair doesn't do the job.

I suspect it's the update that caused the problem, but I'm not sure.

Does anyone have any ideas what to do? Reinstalling Vista is my last option so far.

There's been reports of an ATI video driver update causing this problem - but I'm unsure if this is your issue. Regardless, boot up the system and as the Windows screen first appears - start pressing F8. This should get you to a screen where you can launch Startup Repair in the Recovery Environment and hopefully will allow you to get into Windows without too much trouble.