I have always had my itunes on an external hard drive with no problems.
My old external drive (G) was getting full so I bought a new one (H).
I had both plugged in to the computer to transfer everything across. The itunes library set up fine and the pathways all read 'H'.... and it plays great and new additions to the library are added no problem.
Then I downloaded the new 10.4 version of itunes to H. When I tried to load/update it comes up with the 'G invalid' error. I am assuming that as the last version of itunes was originally downloaded to G (but since seemingly moved across to H with no problems)then something somewhere is saying its still there, even though it isnt (have never plugged G in again since transfered everything from it) and all file paths are marked 'H' and playback etc is working perfectly.
Could anyone give me a clue as to why??? And how to solve???
I think you need to seperate the iTunes Programme files from the "i Tunes" folder. The first is the system file, and I have it on the C:Drive (C;/Programme Files (x86)) as updates are easier to update there. My "i Tunes" folder, essentially a data folder with album artwork, itunes media etc, is on my data partition (F: in my case)ie(F:/My Documents/My Music/iTunes). When the updates come , only the actual programme (system) files are affected. I also back up all "My Documents" ,music, Word, Photos, Outlook etc to a second HD using Freefilesynch or Synctoy daily, and sonetimes to an external HD.
Will look at my detailed settings further if you wish.