I've never used the upgrade option, does it come with it's own serial number or does it just work off the old vista install? The code you're getting now is a set up/ boot loader error.
Whack in an Ubuntu CD or similar, use that to copy the files across to a removable medium. If its down to you having crappy memory, though, it'll crash like a mofo. Replacement memory should, in theory, just let you boot into a slightly unstable windows and then sort everything from there.
You could boot from a Linux live CD & copy your files out to a USB drive, before re-installing Windows. IIRC you can do a clean install from the W7 upgrade disc.
Would it work if I stuck a new HDD in there, installed vista on it then upgraded to 7, then tried poking around on my current HDD for my files etc? I've been looking at getting something with SATA-III to maybe make things run faster before this all happened.. I tried doing a clean install from the upgrade disc but it gave me the two-line error message in my last post. And in terms of copying things to a USB drive, I don't have any bigger than 80GB and I'd need something with about 10x that... Really appreciate all the help btw
Try running one stick of ram and see if it boots, if not try the other one and see what happens, if it boots then you can get into safe mode and create a partition, then reinstall on the new partition and delete the old windows install after.
