Yes you *CAN* stop programs writing to the SYSTEM32 folder but I don't think you really want to... there are lots of perfectly innocent programs that need to write to the SYSTEM folders and you don't want to stop them.

If Firewalls "kill your PC" then you are not using them right.
Download Spybot Search & Destroy to scan, remove and innoculate your machine from spyware attack...

Also - why is this in the VB forum?