Had this issue with one of my clients: he was unable to open spreadsheets from his desktop or from his Windows Explorer. Double-clicking on the file opens a new, empty Excel session, and an error message is displayed.
After a quick search on the Microsoft support site, I found a solution.

When attempting to open an Excel spreadsheet from the desktop or from Windows Explorer (or any other program), a new, empty Excel session is started, and an error message is shown:

Quote
Cannot find the file path (or one of its components). Make sure the path and filename are correct and that all required libraries are available.

or

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Windows cannot find FilePathFileName, Make sure you typed the nam  ...