Sound messed up after installing driver?

Hi! I have had my notebook 2000 for 2 years, and there has never been a sound problem with it. Today, i downloaded and installed 3 drivers from the HP site which is Realtex High Def Audio, AMD graphic, and something abou enhancemrnt. After the installation, my computer has no sound. There is a tick x on the sound. When i click on it, a troubleshooting window opens, ran for a while and said it was an unidentified error. So i went to device manager and deleted the Realtek audio driver but it was no help. I also tried running a system restore but the system can not restore which i think the driver caused the problem.
Can someone please help me because this is really frustrating?