Computer Graphics

So I had lost the ability to hear sounds from my computer and tried many things to restore its original sound device and nothing worked. Then I did a system recovery as my final option and it did something to my computer graphics or the way it ran the games I played. I use to be able to play a game with : These requirements

Windows XP or Vista 32 CPU
Intel Pentium 4 class processor or AMD Athlon XP, at 1.5 GHz or faster
Video Card
GeForce FX class or ATI Radeon 9600 with 128MB of dedicated VRAM or better
System Memory
512MB of RAM or more
Sound
16-bit, DirectX compliant sound card
DirectX
9.0c or better
Drive Space
2.5 GB of HDD space, plus additional for new game content
I dual cliented this game with no lag at all and sometimes did 3 of the games up at once with very little lag. This is my computers information :

Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_qfe.070227-2300)
Language: English (Regional Setting: English)
System Manufacturer: Gateway
System Model: W3650
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: Intel(R) Celeron(R) CPU 440 @ 2.00GHz
Memory: 1016MB RAM
Page File: 781MB used, 1144MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode

What I am trying to figure out is after the system restore I was no longer able to run x2 -3 games at once with no lag I got mega lag with just 2 games going. Does anyone have any info on things that the system recovery changed causing these performance issues . Plz Respond back and Thank you for taking the time to help