As far as the IE9 problem your probably using IE 32 bit in a 64 bit OS. Delete the 32-bit and attach the 64-bit version of IE "Internext Explorer (64 bit)" [something like that] top the taskbar/desktop instead of the other(32bit/the one that doesn't say (64 bit)). And the BSOD is from the...
[MSE]Microsoft Security Essentials is fine. I don't use a anti-virus on my main computer because no one else touches it, but I use MSE on any others and it is fine. Granted, I could get one without downloading but that is a different topic.
I'm not saying your stupid but this happened to me, sadly.. If your laptop has a physical volume control, check it to make sure it wasn't turned down accidentally.