OK, so I downgraded to XP on my machine -- a Gateway GT5628 -- and let me tell you it wasn't easy.
First I tried installing XP Pro from a CD. BLUE SCREEN.
Then I tried slipstreaming SP1 into XP Pro CD. BLUE SCREEN.
Then I tried slipstreaming SP1 and SP2 into XP Pro CD. BLUE SCREEN.
I found out the BLUE SCREEN's were because I needed new drivers so I installed the DriverPacks BASE software (http://driverpacks.net/) and then installed the CPU, Chipset and MassStorage driver packs.
I tried installing the DriverPack + SP3 and it got into the install but then failed on the Product Key. So no longer a BLUE SCREEN but I do have a THIRD useless CD Coaster at this point.
Turns out that if you slipstream a SP3 XP disk under Vista, that Vista will screw with at least two of your files in the "I386" directory: PIDGEN.DLL and DPCDLL.DL_. The solution is to find an XP machine and slipstream your XP install disk under XP. Alternatively, supposedly you can still do it under Vista but copy those two files from your SP2 install or directly from the "I386\ic" dir in SP3. Anyhow, I just slipstreamed under XP and it worked.
Finally Install and you're good to go. I did a clean install on a fresh partition and everything worked pretty well.
The "Media Card Reader" and Network drivers for Vista from the Gateway site work under XP. I grabbed the latest video drivers from NVidia. The only issue was audio drivers and those I got from the Intel website.
So now XP works just fine and dandy on my GT5628 after about 10 tries to install that failed.