First thought is to reinstall your Sound adapter or onboard chip drivers either from
the disk that came with the computer or adapter.

To see if the drivers are installed or have a problem:
Right click MyComputer
Click Properties Device Manager tab
Click the + next to Sound, Video and Game Controllers to expand that device category

Is your sound device listed or does it show any conflicts?

If you do not know what you have then:
Remove the cover and look at any names/numbers that will be printed on the
adapter/chip.
Or
Download/install/run
Everest (previously Aida32):

http://www.lavalys.com/products.php?lang=en

Post the information requested in a response to this thread. To find the Everest
info you need to post, run the Everest program, and click the + sign next to Computer
on the left side of your screen then click Summary.

Then Right click the information on the *right* side of your screen and select Copy.
You can then paste the information in Notepad or paste it directly to this newsgroup.

Everest will tell you a lot about what's inside your PC. In addition to telling us
the *Brand and Model Number* of your computer, please post back the information
Everest reports for your:

Computer manufacturer and model
Motherboard
CPU
Chipset
Sound device

--
Brian A.

Conflicts start where information lacks.
http://www.dts-l.org/goodpost.htm

"liv" wrote in message
...
Hi I do not have sound on my computer for I believe I
changed the driver? I reinstalled windows 98 but it
didn't help. The error message I get is as follows:
Could you please help me reinstall my driver or whatever
the problem may to so I have sound? I run windows 98.
Thanks!

0xC00D11BA: Cannot play the file
Windows Media Player cannot play the file because there is
a problem with your sound device, such as a sound card or
sound controller. You may encounter this error message for
one of the following reasons:

Your sound device is in use by another program. Quit other
programs that may be using your sound device, and then try
to play the file again.
Your sound device is not functioning properly. To
troubleshoot the problem, see the Sound Troubleshooter in
Windows Help or refer to your sound device's
documentation.
You do not have a sound device installed on your computer.
Install a sound device, and then try to play the file
again.
Error ID = 0xC00D11BA, Condition ID = 0x00000000