I actually had the problem too with the demo. It was driving me nuts!

After a good long search on google, I came across this solution.
1. Go to the Control Panel.
2. Choose sounds.
3. Click the sound tab.
4. There should be a list of all the different sounds that window makes in different situations. You want to choose the default beep. In the sounds list, choose none.
5. Click OK.
This will get rid of the windows beep. HOWEVER, no you have to deal with an even more annoying system beep when choosing a track.

Don't worry I got a fix for that too. Even though I don't recommend because it does alert you about overheating and such. But if you take good care of your laptop then you shouldn't have any hesitation doing this.
1. Go to the Control Panel
2. Device manager
3. Click view, then show hidden devices.
4. Scroll down till you hear non-plug and play drivers, then expand it.
5.Right click Beep and choose properties.
6. Click the driver tab
7. In the Startup type option, choose disabled.
8. Click OK.
That should do it. It doesn't treat the underlying cause of the problem, but it will stop the symptom for now until it is resolved. This certainly worked for me. I hope it works for you guys as well. And in the end, become less annoyed.
Cheers