I will try to help you.
This issue is there for many users
See all the itunes music listed there or not
open itunes and check for a song with exclamation mark
Find it in the folder and double click it
Restart the iTunes
Check the same song in iTunes and play.
I cannot find it in the folder
What is thre inside the Music folder ?
I am not at that computer now. Can I email back when i'm there?
ok, If you are not able to see music files there, it will be in this folder. C:\users\username'[your computer name]\My Music\iTunes Check in your system to see whether you got such a folder. Double click the music file if you can see it.
Also using the search option of Windows 7
to find the exact location of the music file.
Let me know how it goes.
Don't forget to click the ACCEPT button so I get paid for my work.
What is 'computer name'?
Its the name that you have give to your account
While creating the Admin account or Guest account you will be giving a name for the account
If you open C:/Users you can see such folder