[jyl]

I think you'd better bring the computers to a local Mac repair guy, if you can find a good one.

I can think of a couple more things to try. 1. Shut down Macs and restart. 2. Disk Utility -> Verify Disk and Repair Permissions. 3. Re-install Office and try opening the files again. 4. Buy an anti-virus app and scan.

But honestly it is super weird that this is happening to both desktop Mac and notebook Mac. That is right? You are having the exact same problems on both machines - Excel files missing, mysteriously found in Trash, when you try to open them in Excel you get "can't find" message, and it started happening at the same time?

Normally at this poing I'd be suspecting corrupted files indicating impending hard drive failure. But on two machines at the same time?

BTW, are the hard drives nearly full by any chance?