Thanks for the quick replies!
The scanner seems to be ok. Light is on and when I try to scan from the computer, the scanner activates as though it is going to work then error message comes up.
I suspect you may be correct about the RM restrictions. I have found quite a few things don't work fully on those machines when I have no problems at home (e.g. updating school website), even though I always use an admin account. I'll get onto RM and see if they can help.