I have an old Advent PC that formerly had XP as OEM, but got upgraded with a spare copy of Win 7 Pro to make everything compatible on my network. The PC clearly can't cope with Win 7 without spending another £50 on memory, so I decided to bin it. I thought I'd just clean re-install it with XP from the OEM recovery disk, and possibly give the PC away to a worthy cause. However, once the recovery process starts after booting off the Recovery CD, it gets about 9% into the file unpacking phase, and then can't unpack any of the system files. I have to "cancel" about 5 zillion dialogue warnings, or hard stop the PC to escape from the jam. Why won't an XP recovery disk work? I assumed it would unpack and overwrite anything on the disk, even if its a later operating system - eg XP easily wipes out Vista. Has Win 7 somehow prevented this? If so, is there a way to un-install Win 7?