The story so far...
I got a GeForce 8500GT because I couldn't find the 7200 or 7600. It was on he HCL so I figured what the hell.
After successively trying to install Ubuntu and then trying to restore XP's bootloader, my MBR is a barren featureless desert land. I don't know what I did but I can't boot windows without the setup cd being in the drive. Small issue, just need to rebuild boot sector. No problem.
As a result of all this though, I've decided to go ahead and install vista first thing because then I can use EasyBCD to fix all my screw ups in one go. It is however, going to delay my installing OSX or anything else for that matter for a little while till I get my hands on Vista.
So thanks again to everyone for all the info. Will probably have loads more questions when I actually get down to it.

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Desktop:
AMD Athlon 64 3000+
MSI RS482M2 Motherboard
2GB DDR400 RAM
1x 80 GB IDE HDD
2x 120GB SATA HDDs
Creative Audigy Sound Card
GeForce 8500GT PCI-e Card

Laptop:
CPU
AMD Turion 64 X2 Mobile TL-50 (Socket S1 638), Codename: Taylor,
Cores: 2, Instructions: MMX, 3DNow, SSE, SSE2, SSE3, x86-64
Motherboard
Quanta 30B7
Chipset: Nvidia GeForce 6150
Southbridge: Nvidia nForce 410/430 MCP
Memory
4GB Dual Channel DDR2 RAM
Sound
Conexant HD Audio