I have Windows 7 and the latest iTunes. My original user account, where my library is, seems to have contracted a virus so it's sky-rocketing my internet usage. I created a new user account, but I need to transfer my library, since I want to delete my old account to delete the virus. I've tried using an external hard drive, home sharing, and changing the library location to a public file, but nothing seems to work.
Under the old user, launch iTunes, then Preferences, then the Advanced tab and discover the "iTunes Media folder location".
Switch to the new user and launch iTunes. From the advanced tab, verify that the new user location path corresponds to the new user name. If it doesn't, quit iTunes, create the iTunes Music folder (using the path structure of the old location as a guide).
Relaunch iTunes. Set the location to the new folder you just created.
Quit iTunes and use Windows Explorer to copy everything in from the old user folder to the new user folder. Launch iTunes from the new user and your music should be there.