Can't do a system restore.

Hi, I need to do a system restore to fix a small sound problem, but each time i try, I get the following message:
"System restore failed to extract the file (C:\) from the restore point. An unspecified error occurred during the System restore (Ox8oooffff).":mad:
I have disabled the AVG Anti virus and disabled the firewall when doing this.
Can someone please give me a solution to this, thanks, Graeme.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM) i3 CPU 540 @ 3.07GHz, Intel64 Family 6 Model 37 Stepping 5
Processor Count: 4
RAM: 4087 Mb
Graphics Card: NVIDIA GeForce GT 430, 1024 Mb
Hard Drives: C: Total - 953767 MB, Free - 483975 MB; E: Total - 131061 MB, Free - 41028 MB; F: Total - 190771 MB, Free - 18174 MB;
Motherboard: ASRock, H55M-LE
Antivirus: AVG Internet Security 2013, Updated and Enabled