Definitely a clue within... Yes, check for UDMA, also if it was a large drive and the restore disk may not have large volume support, etc. But the main spot to focus on is why it took s-o-o long to load Windows on a new drive. An hour tops is all you should be looking at.
So I bought a new HD and installed XP Home back on it. That took days to complete
Also check for problems with hardware such as RAM and possibly other core hardware such as optical and floppy drives. When installing Windows, do not have any printers, faxes etc connected as well. Get a base unit working first and tested, then install peripherals one at a time with reboots in between just to be on the safe side.
There's no place like 127.0.0.1