Microsoft Excel Format Cells with missing selection

[celestialbunny]

Hello fellow community, my friend seems to have this kind of issue whereby there are no selection of formats under Cells. I have tried to offline and online repair, followed by reinstall the O365 but to no use. The selection is not appearing under Format Cells. "Number" is not the only category missing. I have also thought of restoring the default software settings but unable to find it according to this guide. 

[#2]

@celestialbunny 

Not sure, but I'd check Windows regional settings and Windows number format if they are the same for the left and right screenshots. 

[#3]

Well, regional settings shouldn't affect the negativity and positivity of a number. Hence I handpicked this screenshot as the best example to showcase.