recently my Windows 7 x64 machine started to act very weirdly, a lot of programs would crash randomly. The one application that would consistently crash was Team Fortress 2, after loading a map, I suspect it is because it uses a lot of memory. Also my hard drives are trashing constantly after a while, but I can't see any significant IO going on with Process Explorer. This could indicate page file trashing.
I ruled out the usual suspects, no virus, no spyware that I could detect with various preinstalled, or online, or CD based tools. Manual inspection of the startup, services and drivers did not reveal anything significant.
So I created a second clean install on another drive, which works just fine and rules out hardware problems also, expect for the hard drive maybe.
I then started to compare the 2 installs in similar situations, and noticed that on the bad one, programs use an enormous amount of virtual and private memory, think in the GB area (as far as 5GB), whereas on the good one the values are much more what I would expect, in the 0 to a few hundred MB area.
The main difference between the 2 installs would be all the dev tools I did not install on the second one and a few games. The drivers are the same, the AV is the same.
I am starting to suspect a corrupt VC++ runtime installation but apart from that I have no idea what could be going on ? Any suggestions ?