Sound problems

I was having some trouble playing music in Yahoo Launchcast radio. And while
trying to discover the problem, found that it also was an issue in Quicktime.
So I installed new versions of Quicktime and itunes for windows. Up to that
point the sound errors were only in those two applications, and were that the
music was distorted. Now, I am having errors with all sounds, so I
uninstalled the quicktime and itunes software, restarted my computer and
checked dxdiag sound tab again. I now have this error message when checking
the sound:

DirectSound test results: Failure at step 19 (User verification of
software): HRESULT = 0x00000000 (error code)

And the sound does not play.

In addition when using the windows device manager, the sounds there play
very faintly even though all volumes are maxed as is my speaker volume.

So essentially, my attempts to fix an annoyance have turned into a big
problem. Please help if possible. Thanks.