I'm going to try and help you here, I'm no expert on Itunes nor computers but here's the way I THINK I'm set up. BTW, I'm runnning windows 7 . When I right click on the itunes icon on the desktop and hit "open file location", it is showing that my itunes player is on C drive, my itunes music folder is on my E drive. Just for the record, do you have two hardrives in your pc (or one external) or do you have one partitionned? I have two hard drives in mine, C and E.
I try to keep my data files (music, photos, etc) on one hd (E) and program files on another (C). I think the itunes player is just a program and the songs in the library can be anywhere else on the pc, even on another hd, but itunes needs to know which folder and where it is.
Once itunes opened up, if I click on edt, preferences, advanced, it will show you where your itune music folder is listed So if it's not showing the new location, click the change button and point it towards your new location.
To get your files back into your itunes, just click music at the top left, then click on file, add file or add folder (for albums) and then navigate to where your itunes folder is in your new location.
You can select and hold shift and select multiple files/folders or select one folder at a time.
Hope I don't confuse you. I just went through heck and back trying to set up a Western Digital media live player to be able to play my music, movies, photos from my pc to my television.
PS: If anyone out there wants to correct me, please be my guest.
SM