No Realtek driver been reconised

[Danny90]

Hey here is my computer setup:

Microsoft Windows XP Home Edition, Service Pack 2
DirectX 9.0c.
AMD Athlon 64, 2000 MHz (10 x 200) 3200+,VIA K8T800Pro.
768 MB (PC2100 DDR SDRAM).NVIDIA GeForce 6600 GT (128 MB).
hdd's: ST340012A (40 GB, 7200 RPM, Ultra-ATA/100), ST380211 AS SCSI Disk Device (74 GB).
Drives: CD-RW CDR-6S48 (48x CD-RW),TSSTcorp DVD-ROM SH-D162C (16x/48x DVD-ROM).

Right so i recently i was playing S.T.A.L.K.E.R then i went out the room came back in and my pc was restarting over and over so i disabled auto restart on system failure, Then ran tryed running safe mode but yet it still restarts after windows boots up no matter what I did. I did a full format get everything back working after hours of installing but then i go to play my favourite playlist on winamp and get an error. So i went into the device manager to find my realtek drivers werent there, Also on sound properties everything is greyed out like i have no drivers installed.I unistalled and reinstalled the Realtek drivers v 401 but yet still nothing shows up on device manager and on sound properties. I still cannot find out what the problem is I have tryed everything please help! Thanks.