30 years on mainframes, that is impressive.
Doing a reinstall is fine, lots of permutations to ponder on.
Kernel - suggest banging in a new kernel, 3.2 with pae and bfs is probably what you want with all that memory. Note first boot take a while, press Esc to see what it is up to, and have patience.
Try getvirtualbox, script than does the install with guest additions. It works really well. I have half a dozen virtual machines to play with, and no rebooting etc.
I also re-iterate the system recovery idea. Three choices, I plump for using a clonezilla live cd to back up my system. (Maybe RBS's Indian branch should have been better at recovery.....)
As a bonus when you select a screensaver try the BSOD one. You may recognise a few of them, some are ancient.
Keep asking questions, only way to learn. If you are a glutton for information on linux rummage in the documentation section of synaptic.