constant, random BSODs

[alx13]

I've posted before and wasn't able to get much help, but thought I'd try again with a new history of BSOD reports. These seem to be random, and are very frequent - often multiple times per day. The only consistent thing seems to be that I think they are almost all when using the internet, but then again, that's pretty much always.
I used to have Norton 360, but uninstalled that on someone's suggestion and am using MSE, but still having the same issues.
Perhaps related, as most crashes occur when I am using Firefox, is that Firefox itself crashes frequently, sometimes recovering, but sometimes just freezing the whole machine, requiring a reboot (and thus no BSOD dump or report). Not sure how to go about trying to debug those. I'm trying to switch to Chrome now to see if that resolves anything.

Thanks.

System Specs:
Windows 7 64bit, original OS
System is around 1-1.5 years, no OS reinstall

 

[alx13]

additional info

I've run memtest for about 12 hours with no errors.

I ran driver verifier for awhile, and uninstalled MagicISO as it seemed to be causing some problems. At a later point, after some changes (I don't remember what exactly), verifier was causing it to crash at bootup (these BSODs should be in my attached report).