We are using Quickbooks Pro 2002 Multiuser, we had the quickbooks files on a network share. I've copied the quickbooks files to a different network share and now I get a message saying "This company file has been opened by another user. Ask that user to switch to multi-user mode so you can use the company file."
No other user is actually using the file at the time I tried to open it. This is happening on 2 different computers. I also tried to install Quickbooks on another PC and get the same message.