Using an upgrade Windows 8 disk, I upgraded from Windows XP to Windows 8 (32 bit) with Parallels 9. I would like to install the 64 bit version of Windows 8 but the installed 32 bit OS will not mount the DVD. I note from other forums that users have got around this issue with standalone PCs but has anybody achieved this with Parallels? I understand that 64 bit Windows 8 requires a clean install. I have set up a second VM under Parallels but understandably this doesn't accept the registration code as Windows 8 (64 bit) cannot find an existing version of Windows on the system. Grateful for any help/advice.