I looked at the TIDs, but they didn't really apply. The files I am trying to open reside on the hard drive, not the server. I looked in options and the "ignore other applications" box was unchecked. I tried checking it and got an entirely different error saying, "Cannot find the file '[c:\documents and settings\user\my documents\[filename].xls' (or one of its components). Make sure the path and filename are correct and that all required libraries are available. <ok>" This seemed worse than the original error so I unchecked the box again. The original error was titled "Microsoft Excel" and said, "A document with the name '[filename].xls' is already open. You cannot open two documents with the same name, even if the documents are in different folders. To open the second document, either close the document that's currently open, or rename one of the documents. <ok>" In either case, the document ultimately opens and I am able to save it.