Hello all, I recently built a new system with AM2, Asus M2N32 SLI mobo, X2 4600+ CPU, 2GB RAM (corsair), 550W PSU, Geforce 7950 GX2. This is my first rig and after much help from others, I managed to get it working. Everything is fine - I built it for gaming and games work perfectly. The only problem I have is that whenever I leave the computer on overnight, after I come back to use it, there is a lag in XP, for example, when I open or close windows and the whole system seems a little slower. Using CPU-Z, the CPU is still working at the same speed - I have disabled Cool N Quiet. Temps seem normal hovering around 40C or so. I checked to make sure the cooling for the CPU is properly set up (fans, thermal paste etc). I never suspend or hibernate my system when leaving it on overnight. All my BIOs power settings are at default and I never changed it. In XP, I set up my power settings to never switch off, only the monitor. I am at a complete loss here - is this Windows related or hardware related? Many thanks in advance for any advice.