I tried to install SP1 on a customer's Vista laptop today. It took about 2 hours then eventually a black screen appeared and it started working through 95,583 files until it reached 3790/95583 and stuck, where it remains now.

The white writing is as follows..

!! (4) !! 3790/95583 (wdf01000.sys)

The screen flickers as if trying to move on but can't get beyond this point.

I have tried restarting using last known good config but the same thing happens.

I have also tried the repair option of system restore but that ran for about 4 hours without anything happening.

Is there anything I can try or would it be easier to backup and reinstall from scratch?

I have fixed the problem by simply copying another copy of wdf01000.sys from the winxs folder to c:\windows\system32\drivers and the service pack installation carried on normally after that and Windows booted with everything working..