In previous version we were able to alt-tab between programs running on the client computer. In Windows 8 and above and Server 2012 this is no longer working.
The solution is:
KB related to AutoHotkey http://www.autohotkey.com/board/topic/84771-alttab-mapping-isnt-working-anymore-in-windows-8/
The fix is...
Setting UIAccess=true in the exe's embedded manifest appears to solve this problem for AutoHotKey
Since this is hardcoded this has to be implemented. Please restore this function ASAP!