aero alt+tab functionality [SOLVED]

somehow my alt+tab function is back in the old style like in windows xp

i want to get it back to aero style

i tried disable/enable aero peek, change themes, advanced visual options, aero troubleshooting and of course tear down google for answers. but no solution
i create new account and there it work normally. is there any registry key or something to fix it?
windows 7
Answer #1
This is enable just by enabling Aero. Tried restarting the computer?
Call it a fluke, but I have noticed Windows 7 malfunctioning a lot lately.
Windows 8 is much better, I would recommend the upgrade (and by upgrade I mean fresh install of course).
Answer #2
Solved this problem on IRC for him.
Registry key.
DWORD named AltTabSettings to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer '
Changed it from 1.