After the directory disappears you will want to wait a specified amount of time as you have stated. However, I think that the command you want is ...

DECLARE SHORT ExitWindowEx IN Win32API SHORT uFlags, INTEGER dwReserved

The values for uFlags are

0 - Log Off
1 - Shutdown
2 - Reboot
3 - Force Reboot
4 - Power Off

The value for dwReserved should always be 0.

If there are applications (such as M$ Word or Excel) with unsaved documents opened you can obviously see the problem with the Reboot option.

Good Luck.