I have Windows Vista Home Premium on my Dell laptop. For a few days now, seems like after one of the Windows Updates on 24 or 25 Feb, I log on it and it acts like it is logging on fine but is sloooooow. Then says "Preparing Desktop" and then screen is blank?? I have done all tests for Dell laptop, Windows Diagnosis, full system scan, and my laptop is always updated w/ Microsoft Windows Update, and Microsoft Security Essentials. I keep doing a Safe Mode to do Windows Restore to earlier date and then it works like it ought to, but this is a pain. What could be the problem? thank you.