Moving backed up mucic from internal hard drive back to mac

Okay everyone,

So my brothers Mac had tiger and it was rrrrreeeeeaaaaalllllllllyyyyy slow (not to mention the Mac is old and needs more ram), so he decided he wanted to install jaguar instead (dont ask why, he just did, as much as i advised him against it) so before he did, i put all his music onto my external hard drive (but i wasnt on administrator), i entered the password and everything works fine.

But i go to put the music back on, and it says something like 'you do not have the priviliges to do this or something of the sort.....and i got that 'oh sh*t' feeling....

Was it because i was on another account???


Is there any way around this?

Thanks,
Tanner.