Well, it looks like I have some major hardware issues. I removed all my ram and started testing it by trying to boot into Win 7 with different combinations of ram (one gig at a time). I had 3 gigs installed when the problems first started (2 @ 1GB chips and 2 @ 512MB). It turns out that at least one of the 1GB chips was bad, because after installing just 2 of the 512MB chips, the system booted. Now I have 2GB installed (4 @ 512MB in dual channel mode). The problem now is that despite the system booting, it is so slow and unresponsive it's virtually unusable. There must have been some collateral damage somewhere.
Did anyone look at the logs I posted in my last response, and if so, does it give any clue as to what may be going on? Thanks, in advance for any help provided.