Thanks again, Logit. It now creates three sheets when I used File -> New -> Blank workbook, which is OK.

But the main problem still remains: if I launch Excel from the taskbar, or create a new file using Ctrl + N, it opens Sheet3 with the cursor in cell C5.

By the way, I'm using Windows 10 and Office 2016. For some reason, the thread says 'Windows Vista' / 'Office XP' - I thought I'd updated my profile. I'll try to update it again.