Hi sootielilarose,
Thank you for posting in the Microsoft Community.
Apart from the issue, how are you doing today?
Windows Media Player allows you to play your favorite music, videos and movies. I can imagine as to how it might feel if such a privilege is lost. In your case, you seem to have an issue with music files missing from Windows Media Player. I understand that it must be frustrating. But, we will proceed together as a team and try to resolve the issue for you.
Please answer the questions-
1) What exactly happens when you try getting into the “timesheets”?
2) Do you get any error message or error code?
3) Have you made any other changes on the computer prior to the issue?
I would like more information regarding the issue.
Method 1-
You need to perform a System Restore to undo the changes made on your computer.
Refer the articles-
http://windows.microsoft.com/en-US/windows7/products/features/system-restore
http://windows.microsoft.com/en-US/windows7/Restore-system-files-and-settings
Note: Performing a System Restore will undo any changes made on your computer earlier. You may also lose unsaved information as well. Proceed at your own risk.
Method 2-
I would have you run the fixit-
Fix Windows Media Player video, and other media or library issues
http://support.microsoft.com/mats/windows_media_player_diagnostic
Method 3-
I would have you refer the articles-
Windows Media Player frequently asked questions
http://windows.microsoft.com/en-US/windows7/Windows-Media-Player-frequently-asked-questions
Windows Media Player Library: frequently asked questions
http://windows.microsoft.com/en-US/windows7/Windows-Media-Player-Library-frequently-asked-questions
Do let us know if you need further assistance. We will be happy to help. We, at Microsoft strive towards excellence.
Thanks.