MSE not playing well with STALKER complete 09

[no51]

Microsoft Security Essentials isn't playing all too well with the mod/installer for STALKER Complete 2009. It pegs my quad core and causes general system unresponsiveness. I'm pretty sure SC09 is the culprit since it's the only new program I've downloaded/attempted to install since I switched from Avast to MSE. Even navigating to the folder where I saved it causes it to peg. At first I thought it was an Opera problem since I just launched it from there but subsequent tests say differently. Anyone care to confirm/disprove what I'm experiencing with their own system? I'm using the automatic installer. Also, anyone have experience with the mod? I stopped playing it since I got it around the same time I got Fallout 3. Applying FO3 tactics to S:SOC is a sure way to get killed.

[IAmGhostDog]

I'm using the automatic installer.
Also, anyone have experience with the mod?

Is this the one you're using?
STALKER Complete 2009 1.4.1.exe (Steam automatic)

It's an excellent mod.
I've finished and now I'm just roaming the Zone.

But I used this:
STALKER Complete 2009 1.0 + STALKER Complete 2009 Patch 1.32

I'm running NOD32 v4.0 with zero issues.

[no51]

Ended up using the manual installer, although I am curious as to why the automatic installer sets off MSE like that.