I have installed MS Office 2003 on some new IBM ThinkCentres, model# 8215-22u, and am having a problem saving existing Excel files on our network. When the file is on the hard drive, I don’t get the message. This is the message: "The file may have been changed by another user since you last saved it. In that case what do you want to do - Save a copy - Overwrite changes". We have been using Office 2003 on other model ThinkCentres for over a year with no problem. We have installed all the Microsoft updates, installed all hardware updates and searched the Microsoft knowledge base and nothing works. No one else has the file open. When I create a new file, I can save it, but when I reopen it, I get the message. Command antivirus is running on these computers, but it is also running on all the others. I would appreciate some suggestions. Thanks.