My issue: In the shaengarne dam area, when I left for the bridge, my laptop instantly shut off. I rebooted, but as soon as I tried to log into Windows, it shut off again. So I tried Linux (I have a dual boot) and that shut down as soon as I entered my password. Removed battery, then could boot into both. Played various other games for hours, no issues. Heat, anti-virus and anti-spyware all checked out. Started Icewind Dale 2 again, and the issue happened again in like ten seconds. Currently reinstalling, but don't really want to start over if there is a fix. Ideas?

Specs:

Windows 7
AMD Phenom II triple core
3GB ram
ATI moblility radeon HD 4250

That sounds more like a hardware problem than a problem with IWD2.
I would start by running a memory checker like memtest.

Check Windows Event Log if there is anything suspicious prior to crash.