When I type the number 4 in excel, it changes to number 3. It also does it in word, however does allow me to change back to 4. But excel will not allow me to type number 4. How can I fix this?

Does the 4 work in any software? Does the problem occur on the number keys AND the numeric keypad or just one of those?

It seems fine when I type into Google, and a few other Sage software systems. It does it on both numeric keypad & the number keys. Very odd.