Computer lags alot during game

Hey guys

FOr about a month now, I've been experiencing major lag during my games. I'd play for like 20 minutes and then it'd kick in. I get around 9 fps.

I ALWAYS close every process (That I dont need) before I play a game.

And the games I play use the Source Engine, not that it's not important (I dont think).

Thanks for any replies. I cant even play L4D with my friends =[

I tried a fresh install of Windows yesterday, still happens.

I updated my GFX Driver yesterday too, but the problem still occured before yesterday, so that's out.

And yeah, I scan my computer every night and defrag at the same time.

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System Information
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Time of this report: 11/15/2008, 12:03:37
Machine name: HOME-7C63E4EEC1
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_qfe.080423-1303)
Language: English (Regional Setting: English)
System Manufacturer: MSI
System Model: MS-7255
BIOS: Default System BIOS
Processor: Intel(R) Celeron(R) D CPU 3.20GHz
Memory: 1022MB RAM
Page File: 445MB used, 2013MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.5512 32bit Unicode

------------
DxDiag Notes
------------
DirectX Files Tab: No problems found.
Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Music Tab: No problems found.
Input Tab: No problems found.
Network Tab: No problems found.

--------------------
DirectX Debug Levels
--------------------
Direct3D: 0/4 (n/a)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (n/a)
DirectMusic: 0/5 (n/a)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)

---------------
Display Devices
---------------
Card name: NVIDIA GeForce 8500 GT
Manufacturer: NVIDIA
Chip type: GeForce 8500 GT
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0421&SUBSYS_047D10DE&REV_A1
Display Memory: 512.0 MB
Current Mode: 1680 x 1050 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: nv4_disp.dll
Driver Version: 6.14.0011.6921 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 12/5/2007 01:41:00, 5773568 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: nv4_mini.sys
Mini VDD Date: 12/5/2007 01:41:00, 7435392 bytes
Device Identifier: {D7B71E3E-4761-11CF-6768-762400C2CB35}
Vendor ID: 0x10DE
Device ID: 0x0421
SubSys ID: 0x047D10DE
Revision ID: 0x00A1
Revision ID: 0x00A1
Video Accel: ModeMPEG2_C ModeMPEG2_D ModeWMV9_B ModeWMV9_A
Deinterlace Caps: {6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(YV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
Registry: OK
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
DDraw Test Result: Not run
D3D7 Test Result: Not run
D3D8 Test Result: Not run
D3D9 Test Result: Not run

Hope this will help.

Byaa

Hey, just posting solutions for my long-lost problems.

The solution to this was a blocked up heatsink. The heatsink for my processor had so much dust, I had to use a toothpick to pick it out and a hoover to hoover the dust. Using a brush also helps get rid of excess dust.