I had some hard disk problems with a Fujitsu notebook so ran chkdsk which seemed to clean up the errors. The system still ran very slowly, so I decided to do a clean install of Windows 7. I deleted the partitions down to one (700gb) then clicked on "Next". There was a message about "disk fail" but it started going fine, and the first part of "Installing Windows" went reasonably quickly.
But it has been nearly 60 hours stuck on "Completing Installation". Should it take this long?