Yeah it's not a HDD problem, I run main on raptor (10k rpm) and slaves on a regular (7200 rpm?) and I've tried putting one and two slaves on the raptor aswell to ease it up for my regular HDD, makes no difference.
Also yes I have set up cpu affinity using KeyClone, didn't know about the 0 and 2 cores only so maybe I should change that for two of my instances.

But alright so I'm probably not wrong assuming memory then?
Probably going to buy some more either way, but from what I understand buying more than 1GB more (3GB total) is a waste if I'm not running Vista 64-bit? Cause I'm running Vista 32-bit.