I recently upgraded to Windows Vista through the Express Upgrade program HP and others were offering to people who bought their computers a certain time before Vista was released. Anyway,it's been one headache after another. I've already reinstalled Visa 4 TIMES already, and had varying degrees of success. Windows Update rarely works. It'll sometimes download the updates, but fail to install. Another problem is that sometimes I'll be able to download programs (Firefox for example) or drivers and get them to install without a problem, but other times the download file will not extract because the "file is corrupt". When I manage to get into the file and begin install, there's usually an error somewhere in the install (Such as when I was trying to re-install my printer). I've also noticed that when downloaded, Vista can't recognize the publisher of the particlular program
Edited to Add: I don't have my XP CDs (HP never gave me any), so unfortunately, going back isn't an option.

It might be pertinent to note that the first time I installed Vista, I got the Fatal Error Blue Screen, but then tried it again and it didn't give me it. Then the second time when I actually finished the installation is when I started to notice all the nonsensical problems.