External Hard Drive changed name by computer

I have an 80GB Maxtor external HD, that was my picture/music/Back-up drive. A few days ago I started up my computer & my system is reading the drive as Local Disk(G:), but it used to read it as BACK-UP(G:). That means my computer has changed the name of the drive & it will not allow me access to the drive or to access any files on it.
I would love ANY help to this problem, before I spend the $$$ on a data recovery service!!
Thanx