Good Evening All,
I spent about 4 hours last weekend trying to perform a clean installation of Windows 7 (64 bit upgrade version) from Windows XP 32 bit. I spent ages reading these and lots of other forums, trying all the suggestions listed for resolving the slow (almost frozen) installation problem and eventually found the answer.
I have an MSI P35 Neo Combo motherboard and the solution was that I do not have a floppy disk drive installed but it was enabled in my BIOS. As soon as I disabled it, the install went flawlessly and quickly.
Hopefully this might help someone else with their issue and solve it faster than I managed too.