Win 7 PCs cannot read each other's notepads or MS Word docs

Both notepad & Word docs are unreadable on each others PCs. Same setup both PCs.

This is happening from copy/paste to Flash USB drives. Unable to open on OP pc.

Can you provide some more information? Possibly a screenshot of the error? Are you sure the file is not corrupt? How big is the file?

Sorry, should have also said - When i open notepad or Word on the other PC the files open 'blank', empty. No text. Just a blank page. Happening in both PCs. We can save our own docs. to our own PCs O.K. They just open as a "blank page" if we save to flash to send to other PC. We both can open & read our own docs on the flash drivesbut not each others docs.

I can see three possibilities:

1. The files are being encrypted by malware (ransom-ware) and will only decrypt on the originating computer.
2. The files are being blocked by Windows (Right click on the file and choose "Unblock" if that option is available.)
3. The files are being damaged in some way on both machines, but I highly doubt that. Too much of a coincidence.