First, thank you for the feedback. It is really appreciated. Indeed, I saw the reference to igdpmd64.sys on the actual blue screen dump, but didn't know how to identify what that is. (I suppose an exhaustive search of all the files in all the drivers listed in device manager would work, but that seems like the tedious way.)
I looked at the site you referenced. Indeed, I'd looked at it earlier. Here is what is weird. On my system, I show v. 8.15.10.2342 for this driver, with the specific file bearing a date of 25 March 2011. But on that site, the corresponding updated driver is v. 8.15.10.2279, with an alleged update date of 15 Apr 2011. (See
http://support.lenovo.com/en_US/downloads/detail.page?DocID=DS026023) So, is the one on the site older or newer? Judging by the version number, I have a more current version (that came with the machine), because 2342 > 2279. But judging by the date, the one on the site is more recent by a scant 3 weeks. Should I really replace 8.15.10.2342 with 8.15.10.2279 ? That seems suspect to me.
As for the BIOS, unless there is evidence that it's causing a real problem, I'd prefer to mess with as few things as possible, at least until I am confident that the machine is stable. Then, I'll tackle the other things that are out of date.
My apologies if these are stupid questions. I'd love to acquire a mastery of the hardware and systems programming, but for the moment, Java applications pay the bills, and a toddler consumes the remaining time, so I'm farther removed from these things than I feel comfortable with.