Apologies for my first post being a problem... you know how it is. I built a system some months ago which I've never been able to get satisfactory performance from - I get regular lag, slow down and pauses in all applications and games from what appears to be HDD access, but I can't tell whether it's hardware or software related. The system is: Gigabye UD3P Seasonic 650w Q6600 2GB Crucial Ballistix Tracer PC2-8500 (2.0v 4,4,4,12) 1x Samsung 250Gb SATA (windows drive) 1x Samsung F1 1TB SATA (data drive) Geforce GTX 260 Asus Xonar D2X Windows XP Pro SP3 AHCI I have always run a virus checker, mostly Kaspersky, although more recently NOD32 and nothing has ever been reported (including scanning using a NOD32 boot disk). I have also scanned all drives with Malware bytes, Spybot and a number of online virus checkers, all of which show nothing untoward. I have also just worked through the '8-step Viruses/Spyware/Malware Preliminary Removal Instructions', the results of which I have attached. The lag I experience is always present, but becomes more noticeable as HDD access increases - trying to do anything whilst defrag is running for example (like open My Computer) takes a rediculous amount of time, for the hardware I'm running. Can anyone offer any suggestions as to what I should do to track this problem down, is this issue virus related - some kind of boot virus perhaps? Any help is very gratefully received.