Using IE7 and WinXP, fully updated, twice AV protected, ran AdAware and
SpyBot, no problems anywhere.
But, whenever I am on the Internet, my computer speakers (doesn't happen
when using external speakers) 'roar', sort of like a motorcyclist revving
up,or like Darth Vadar's voice with no words.  IT does it twice, then maybe
15 seconds later again.

It does not happen when inside my own computer.

It just started within the last few months, but here been alot of
autoupdates, security patches etc. to various programs, and not well
documented in Restore as to what is what, so I hate to go back.  My system
makes restore point daily.

I've compared the processes running list while online and offline and only
difference is IE itself, msimn.exe.

I can't listen to CDs while online as it drowns out the music.  Or I could
just put in external speakers, but I shouldn't HAVE to!

Thanks for any pointers...

Ann