Hello zatno26bz,
After changing the VT-X setting your machine needs to be power cycled.
With a desktop that's simple.. unplug the power cable for a bit and then plug it back in.
With a laptop you might have to take the battery out for it to accept the change in this setting.
A simple reboot is not enough to apply this setting.
For more details on this issue see also the following article by jmattson:
Trouble-shooting Intel VT-x Issues
Hope this helps,
--
Wil