Partial loss of sound

I have a Dell Dimension 3000 pc running Windows XP. Recently I have been unable to get any sound when visiting certain websites e.g. Youtube, but on other sites the sound is fine. There is also sometimes a loss of audio when I try to play music via Windows media player, although sometimes it does work fine. Anyone have any ideas what's going on? Any help much appreciated.

Look in your Event viewer: rt. click My Computer then click Manage then Event Viewer.
Or: Administrative Tools/Event Viewer or Start/Run/ eventvwr
Open the system as well as the application tabs & look for red X errors. Click error line for details.
Post back the source & event id & Description especially of errors that seem to coincide with this issue.
Also check the Information lines that might coincide with this issue.

How to view and manage event logs in Event Viewer in Windows XP

Thanks. In almost all instances of an error the source is MsInstaller and the event is 10005. There are a couple that are source application error and event 1000

To resolve this problem in Internet Explorer, follow these steps:

1. Quit all programs that are running.
2. Click Start, and then click Run.
3. Type regsvr32 urlmon.dll and then click OK.
4. When you receive the "DllRegisterServer in urlmon.dll succeeded" message, click OK.

If this does not resolve the problem, repeat steps 2 through 4 for each of the following files (in step 3, replace Urlmon.dll with each of the file names below):

• Shdocvw.dll
• Actxprxy.dll
• Oleaut32.dll
• Mshtml.dll
• Browseui.dll
• Shell32.dll


If that doesn't help try start/run cmd

Type ipconfig /flushdns