[jyl]

Just to make sure what the situation is. You have a desktop and a laptop, both Macs running OS X, maybe Mountain Lion. There are some Excel files on the desktop and the laptop (are they the same files, if so how do you keep them synchronized? Or are they different files?). Now all those files appear to have disappeared. Right?

Couple things I can think of:

1. Do a search using Finder. In other words, bypass Office/Excel, use the Mac OS to look for the files.

2. Are you logged in as your normal user? Any chance you logged out then logged back in as a different user, so you can't see the first user's folders?

3. Check your backups.

4. Any other files appear to be missing?

Otherwise - are you using iCloud or other offsite data storage site? Are you using a backup app? Are you using anything that tries to synchronize the desktop and notebook's files? Where did you keep the Excel files - in your user folder | Documents. or on your Desktop, or elsewhere?