New System Runs Extremely Slow - Help

I just completed my first pc build, and the computer powered right up. All the components seemed to be working correctly. So i installed a (non-retail) copy of windows 7. The install took a long time and when it booted for the first time it was really slow. Applications that i opened constantly lagged and sometimes became non responsive. Thinking it was a driver issue, I installed the driver cd's that came with the motherboard and graphics card. The computer is still slow.

Is the slowness caused by the non-retail windows 7 or by outdated drivers? Im still fairly new to computers, so all the help i can get is greatly appreciated. Thanks in advance.


PC SPECS
BIOSTAR A880G+
ATHLON X4 BLACK EDITION
SAPPHIRE RADEON 6570
500W POWERSUPPLY
G-SKILL RIPJAWS 8GB RAM
WD BLACK CAVIAR 250G 3.0GB/S SATA HARD DRIVE

in your BIOS do you have your hdd set to AHCI?

check your HDD ide mode and ram timings (needs to match what's written on the sticks)

i just checked the ram compatability with my motherboard manual and it saws that it supports RIPJAW " F3-10666CL8D-4GBECO" but mine is a RIPJAW " F3-10666CL9D-8GBXL" Do you think that the ram isnt fully compatible?

to anyone still following this thread, i know what the issue is. When I got home, I went to boot up my computer and it couldnt start windows 7 at all! So, I took out one of the 4 gb ram and it fixed it! It started up perfectly and isnt freezing up anymore! Im not sure if the 4gb ram inside the computer is functionig normally, so if anyone knows a good program to test ram, please reply back. thanks for all the wonderful advice and concern.