I am guessing this problem has a hardware or driver interaction, because I only have this problem on one older [2006] Dell tower PC I just recently purchased. I tried several different versions of Windows 10 on this PC (Pro, Home, Home N). The bios is updated, and the graphics driver is up-to-date according to Device Manager. My other PCs/Laptops run Windows 10 Home, Windows 10 Home N, and Windows 8.1 with no problems in any display mode.
On the afflicted PC, when launching a mame rom from AM, AM begins its correct process by switching to a black screen, however MAME is never brought into focus. My exit hotkey will bring me back to AM. This problem seems to only affect Fullscreen Mode and Fillscreen Mode (default). As long as I run AM on this PC in Window mode or in Window (no border) MAME will be given the focus it needs.
Has anybody had success at figuring out what hardware or driver issue causes this malfunction?