Here is a brief (somewhat) overview of my problem.
My brother's motherboard was dying, so I removed his hard drive, cloned it, and put the clone into an older machine I had (I wanted to keep his original HDD intact in case something went wrong). I attempted to do a repair install of XP Home SP2 on his HDD so that it would work in the new machine. The process seems to go smoothly until the reboot. At that time I am presented with the same setup window as the initial repair. I am eventually confronted by a screen stating, "Setup has already attempted to upgrade the following Windows installation." I am a bit confused as to what to try next. I have done this type of procedure before but have never had this problem.
Unfortunately his machine was an Emachine, so it only had a system restore disk. I managed to come into possession of another XP Home SP2 OEM disk, which I tried unsuccessfully, giving me the fore mentioned problem. I then edited the PDI in the setupp.ini file from the OEM (55277OEM) disk to one of a retail (55277000) disk. Still no luck.
I want to avoid a clean install at all costs. I have already backed everything up, but do not want to have to go to the hassle of reinstalling every program again.