I don't think win 10/11 matter. I hope not. Moving to Excel 2021 definitely does matter. Your Excel 2008 sheets should work fine in v. 2021. Just download Office 2021 from Microsoft (google for the link) and install it. You can use it for 30 days trial to make sure it all works. Edit: Oh you are running win 8. No matter. Just upgrade to Office 2021 and see if it all works