random lag spikes while gaming

[socc0rfreak]

Hey, i have had my own home made gaming computer for a while now, and when i play games i get random lag spikes that shouldnt be there. Then all of a sudden it goes back to running smooth and crystal clear. The extremes of going from slide show frames to smooth gameplay has puzzle me... i have tried everything i can think and im lost for an answer...

Here are my specs:

Browser: MSIE 8.0
System OS: Windows Vista Ultimate SP2
System OS Install Date: 5/7/2009 9:08:48 AM
System Make System: manufacturer
System Model System: Product Name
System Serial Number: MT7088K00824934
Main Board Make: ASUSTeK Computer INC.
Main Board Model: M2N-MX SE Plus
Main Board Version: Rev x.xx
Main Board BIOS American Megatrends Inc. BIOS Date: 03/26/08 10:37:53 Ver: 08.00.12 A_M_I_ - 3000826 20080326
Processor Description: AMD Athlon 64 X2 Dual Core 5000+
Number of Processors: 2
Processor Clock Speed: 2600 Mhz
Graphics Description: NVIDIA GeForce GTX 260
Memory Installed: 3072 MBs
Memory Slots: 2 slots
Memory Configuration: 1024+2048;DIMM Unknown Synchronous
Drive Size ©: 152617 MBs
Drive Format ©: NTFS
DVD-RAM Model: TSSTcorp CDDVDW SH-S222L
DVD-RAM Read Speed: 8468 KB/sec (48X)
DVD-RAM Write Speed: 8468 KB/sec (48X)
Monitor Model: HP w2207 Wide LCD Monitor
Monitor Resolution: 1680 x 1050 pixels
Monitor Screen Size: 18.3 x 11.7 inches
21.7 inches (diagonal)
Monitor Manufacture Date: November 2008
Monitor Serial Number: 16843009
Monitor Model: Generic PnP Monitor
Monitor Resolution: 1600 x 1200 pixels
Monitor Screen Size: 13.3 x 10.5 inches
16.9 inches (diagonal)
Monitor Manufacture Date: December 2005
Monitor Serial Number: 10169


I am desperate for an answer... so please help =[

[Aaron_8015]

Do you have any anti-virus running in the background? Or something acessing the HDD often? Have you defraged the drive?

[socc0rfreak]

Ive ran Anti-virus scans with nor esults
Degraged with no results
And no background programs are running

:/