I recently switched to Windows 10 and alt tab is no longer working when any of Microsoft Office program is open.  All of the other programs or apps in my PC works fine when doing alt tab, but it doesn't in MS Office. For example, I'm working on MS Excel, when I use alt tab to copy something let say on another Excel file, I have to hit tab twice. I never do that when I was using Windows 8. I should be able to switch between 2 recent programs that I'm using when pressing alt tab, now I have to do it twice? Is this a known issue with Windows 10? Or is there a setting that I need to tweak? Thank you so much

try this:

In Word choose Office Button, Word Options, Advanced, and in the Display group Check Show All windows in the Taskbar.

KR