When I try to run mIRC I get the following error message:

"Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access this item."

I have no idea why. It used to work on this computer (my laptop), but one day it wouldn't.
The laptop I'm using is running Vista. I've tried running as an administrator but that didnt work, I've tried uninstalling and doing a clean install, I've tried uninstalling and taking the (working) mIRC folder from my desktop and putting it on my laptop, but those didn't work either. This is the only program that I get this error with. Anyone know what I could possibly do to get mIRC working again?