Well the plan tonight was to reinstall Windows on one PC and use the Linux PC while the other one was being put back to a state of readiness.
Well..... that was the plan anyway. The reality turned out quite differently.

First job, reinstall Windows and while thats running, clean the inside of the Linux PC because it's starting to stink and the fan doesn't sound healthy. (So far.. so good). OK, install complete - reboot.

Then the Linux PC starts to smell. I put my hand down the back of the case - nothing blows out of the CPU vent. Oh crap! I switch off the PC and sulk.

The Windows PC finishes booting. Ick! look at those graphics!! Oh well, never mind, we can work on the drivers later, let's browse the Ghost files and start putting some programs back....

Windows balks... not enough space to load Ghost. (what???) I look at the C drive. WTF? There's plenty of room, what's the problem? Check permissions, all OK. So I then alter the boot sequence in the BIOS to boot only from the CD, in the hope that it will start to install off the disc - nope, it still wants to boot from the HDD. (Windows 2, User 0)
At that point I notice I have the option of booting into Windows, or booting into Windows, so just for kicks I pick the second option. Yep, I booted back to my old setup. Took a while for my tired brain to catch on. I now had TWO copies of Windows.

My brain has also burnt out. I'm going to give it a rest and try this again in a few days.... maybe.