If you Can't type numbers or formulas or enter data into Excel cells then it might be a problematic Add-in causing the problem. Here are some working fixes that may help.

Microsoft is making an important change to Excel to prevent attackers from spreading malware or phishing campaigns.

If your Excel files are opening in Notepad on Windows PC, here's how you can reset the settings to make .xls, .xlsx, etc files open in Excel.

Also known as a Comma Separated Value file, a comma delimited file is a standard file type that a number of different data-manipulation programs can read and understand, including Microsoft Excel.