1. Type regedit in RUN or startmenu search box and press Enter. It'll open Registry Editor.
2. Now go to:
3. In right-side pane, create a new DWORD value AltTabSettings and set its value to 1
4. That's it. Now whenever you'll press "Alt+Tab" keys together, it'll show Windows XP styled classic "Alt+Tab" Switcher screen instead of the new screen.
5. To restore default Aero enabled "Alt+Tab" Switcher screen, simply delete the AltTabSettings DWORD value created in step 3. Log off and login again to take effect.