Well i start from the beginning, i build a new system from scratch. The build a fine, Installed Windows and Drivers, ran perfect for a week or so, and than i began getting "stop errors". I came to find the my HDD(IDE) had "died". So i went out that night and bought a Brand New HDD(sATA) Installed Windows and Drivers and now the system is very slow, like when i look at my CPU Usage, it fluctuates from like 10% to 80% when im idling(usually on one core only). So i thought it was the processor, i called Newegg and got a replacement, installed it last night, did a clean install of windows and drivers as well, the system is still slow, CPU Usage still fluctuates, Botting takes alot longer, programs take longer to open, etc. I know it isn't sypware or viruses, as this was a clean install on a brand new HDD, i haven't even used the internet on it yet. Here are my Specs if it necessary: Core 2 Duo E6550, MSI P6N SLI Mobo, XFX 8600GT XXX, 260gig Seagate Barracuda SATA, 700w PSU. So if anyone could help, that would be awesome!

Not an Intel person so bear with me if these settings are not available. Go to Device Manger and expand the Disk drive listing then right click properties> policies. If available check the bullet for Optimize for pefomance. Then expand the listing for IDE ATA/ATAPI controllers, right click on the Serial ATA controller listing and choose properties> primary channel. What does it say for transfer mode? All boxes there should be checked. Run the speed test. If you have more than one SATA harddrive then you can repeat the last part by choosing Seconadry channel.

Might have to setup a performance monitor test. Sometimes the cache in the drive and the system cache seem to fight each other, disable the os's disk cache. Be sure that your sata settings are correct and the bios sees the drive correctly. Could even be a bad sata cable or poor connection or even the controller going bad. The perfmon should help you locate the issue. I read it wrong and answer it wrong too. So get off my case you peanut.

OtheHill, when i expand IDE ATA/ATAPI menu, there is no "Serial ATA" in the list, theres 3 Primary IDE, 3 Secondary IDE and 3 Standard Dual Channel PCI IDE to choose from, but no Serial ATA. The "Optimized Performance" thing was already checked too. jefro, yea if nothing else works, that my next fix i going to replace the sata cable. How would i go about disabling the systems cache?

What mode is the drive running in? Device Manager> IDE ATA/ATAPI> Right click on a primary and select properties> Advanced settings. What does it say for transfer mode? Repeat for each harddrive.

It says "PIO Mode", i only have one HDD.

There seems to be some question as to why it says IDE and you say SATA. You have to resolve that first. What is it? I read it wrong and answer it wrong too. So get off my case you peanut.