Being a self professed IT geek and lover of my music I was distraught when I opened my iTunes this morning and got an error from iTunes stating "The folder iTunes cannot be found or created". After much messing around, I remembered that windows points to registry points for the my pictures folder and rummaged through there and to my delight found that there was also a music entry for this and my entry was blank for one and pointing to a removable hard drive for the other. So to save someone else who is stressing over this is what I did to fix it:
Go to Start --->Run --->regedit ---->Edit --->Find---->Win2KMyMusicFolder and modify the value "My Music" for your complete data path i.e. (C:\Documents and Settings\bob123\My Documents\My Music
There are two entries you need to change,their exact locations are
hkey_current_user - software - microsoft - windows - current version - explorer - shell folders
and
as above - windows - current version - explorer - USER shell folders
Once i changed this, i opened itunes again and all my music was back and itunes was working.
I hope this helps someone else
Gregg