Windows XP lag after leaving computer on overnight

[octop8]

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 slight 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.

 

[progenitor]

if u are downloading data to ur machine when ur leaving it on ....it could just be xp having a really large virtual cache file ... at which point a defrag should do

also

its not xp which causes the majority of lag ...its ur hdd .... hdd's tend to overheat when left on for a very long time ....unless its a server hdd..... doing the same over a long period of time will reduce the burnout period of ur hdd and will consistently make ur machine slower and slower

another tip would be to keep ur machine as dust free as possible
dust accumalation on the cpu heatsink will reduce the cooling capacity of the heatsink .....which will eventually lead to ur processor burning out sooner than needed