Office Home and Student 2010

Very weird problem. I can't open any .xls or .csv files with Excel 2010 anymore. Get error message that Excel has stopped working and will close the program..

Was working fine a couple of days ago. Have tried a System Restore to an earlier date. Repairing Microsoft H&S Office 2010. Full uninstall of Office 2010 and a clean re-install. Nothing works.

Try opening Excel in Safe Mode.
https://support.office.com/en-us/article/Open-Office-apps-in-safe-mode-on-a-Windows-PC-dedf944a-5f4b-4afb-a453-528af4f7ac72

If that works, look at add-ins and disable them one at a time to see if one of them is causing the problem.
https://support.office.com/en-us/article/Add-or-remove-add-ins-0af570c4-5cf3-4fa9-9b88-403625a0b460

Behind every good computer... is a jumble of wires 'n stuff.

Turned out it was an Add-on that had pooched things. Funny thing is I hadn't changed or added any. May have been an Automatic Update.