windows 7 OK
// Simulating a Alt+Tab keystroke
keybd_event(VK_MENU,0xb8,0 , 0); //Alt Press
keybd_event(VK_TAB,0x8f,0 , 0); // Tab Press
keybd_event(VK_TAB,0x8f, KEYEVENTF_KEYUP,0); // Tab Release
keybd_event(VK_MENU,0xb8,KEYEVENTF_KEYUP,0); // Alt Release
Using the same on windows 8 fail.
Tried as guest, admin and "elevated admin".
Other key combinations (special with the win key) also fail... it's not only alt-tab.
Did someone already solved this issue?