For 4 days I've had no sound on my computer. Tried everything and in the end just left it as it was in frustration.

Logged on tonight and sound is working again.

Very strange. Could I have a virus?

I would check in device manager for any problems Mo (Right click on 'My Computer', select 'Properties', select 'Hardware', select 'Device Manager'). Look for any '!' or '?' at the side of your sound devices.
Let us know of any problems.
If your worried about a virus, try running Housecall (www.trendmicro.com/housecall) by Trend Micro. It's a very good on-line virus scan :wink: