Oh !
What scan resolution were you trying at the time of the "freeze" ?
Sometimes, depending on the memory available, if the scan setting is too high, your PC can't cope and the thing throws in the towel !
If you can, try selecting the lowest scan resolution available, usualy 200.
If that does not work.....Hmmmmm.
Are you running any other programmes in the background that could possibly interfere with the scanning process - "scandisk" running to a schedule or some anti-virus software kicking in ?
If the thing is still playing silly buggers, then I would,
1. Switch the PC off
2. Switch the scanner off
3. Disconnect scanner from PC
4. Switch on PC and "uninstall" the scanner software.
5. Go through the install scanner set-up, as if this was the first time the PC is to be married to a scanner.
6. If you have followed the scanner introduction 'into' the PC, then if that does not cure the problem, I fear there may have been a power surge that you may or may not have known about that 'screwed' your scanner and it needs to go to the doctors !
Introducing the scanner multi-pin plug or withdrawing it with power "on" in the PC or scanner, or a combination, is enough to cause grief to scanners.
Does it try to scan at all, or is it a case of once you press the scan button it freezes ?