I've upgraded Windows 2000 to Windows XP Professional. I've BENQ DW1620 DVD drive. I can boot other operating systems and bootable CDs with the drive. However, it doesn't exist in Windows XP. I've removed all burning software and virtual drive software but still nothing. I've spent 12 hours on this issue :-( I can't find any useful by searching the web nor MSDN knowledge base. I'd really appreciate if someone could help on this matter. I didn't want to do a clean install because of have a huge amount of software installed and it would take weeks to reinstall all of that, besides everything else seems to be OK in my system. Edit: After 16 hours of head-banging with Windows XP upgrade I'm finally giving up and installing Windows XP from scratch. Let's spend the next two weeks installing and configuring applications in honour of Bill Gates the whizz kid who has brought so much happiness to us all. That f***ing genious. Edit2: DVD drive works in the clean installation of Windows XP, so this is clearly an upgrade failure that the upgraded system has lost the drive. I've about 350 applications in Program Files folder. It's going to take like forever if I have to reinstall everything. Somebody help me, please. None of the usual tricks suggested, like removing UpperFilters and LowerFilters values from registry or uninstalling driver, are unable to bring back the DVD drive in the upgraded system.