I have just installed service pack 1, and now XP won't start properly. after the WinXp logo and moving blue progress bar thingy, it goes black, and then restarts from the beginning instead of going to the logon screen. it is worth mentioning that i had previously changed the logon screen to a customized one that i got from the net which worked well for years. this poblem only happened after i installed SP1. any thoughts?? many thanks in advance!