New
#11
OK, it looks like Alt+Tab is working as it used to with Excel but only if you've opened up a separate instance of Excel. If you're working in one Excel file and open a second from within that instance, then Windows 10 doesn't let you Alt+Tab out. Very strange considering that Windows 7 had no issue with this. Maybe a bug? Or something to compel users to buy Office 2013...?
In any case, I think I can use the workaround of opening separate instances of Excel. Thanks for all your help, everyone. I hope the OP's problem was similar and can be resolved too.