I am cursed where Windows is concerned. I just can't persuade it to behave properly.
I tend to resort to poking it into a usable state then just don't touch anything for 6 months, reinstall and repeat. It's the only way I've managed to get through with XP anyway. Vista is marginally better for install longevity, Windows 7 looks about the same as Vista. The Audio issues actually disappeared about a month after install and only reappeared recently (no driver changes in the entire time).
I have a suspicion the BSOD problem is most likely due to Dell doing something additional to the laptop. Often laptop makers implement things slightly differently, so whilst the nvidia drivers will work on 99% of laptops, there's always a few that slip through, and with Windows 7 being so new, that % is probably higher.
I did try the Vista ones too, no luck. Probably just a laptop issue. Was annoying though, got OpenGL 3.0 support under Linux and not Windows.

Quite honestly I consider WinaAMP, VS2008 and FF a light workload...
I'm often running 3-4 copies of VS, FF with twenty or so tabs open, WinAMP is running almost all the time and I've a handful of other lightweight apps running.
It's called multi-tasking, something Windows is terrible at.

I'll have a play with audio drivers on the RC when I get it on my laptop if the issues re-appear (hopefully they won't) and I'll probably fiddle with various stuff on my Athlon.
My point with the performance was more than my Athlon XP with the RC responds approximately the same as my laptop (which is about 3 times more powerful) does with the beta. At least for general desktop responsiveness.