dont force 'OOBE baby' to sleep, if she takes time, initially ...

[anandk]

"When you try to restart or shut down a Windows Vista-based computer, the system may take a long time to restart or to shut down."

Additionally, you may receive a message that resembles the following:
Windows is configuring updates.

This problem may occur one or two days after you first start Windows Vista.

This problem occurs because the system must perform maintenance functions to delete unnecessary files. Typically, this process will occur one or two days after the Out Of Box Experience (OOBE) Wizard runs. When this problem occurs, it may take as long as 20 minutes to shut the system down. The process occurs only one time.

suggested solution : just wait for the process to finish once. never rush !

this happened to me, hence posting my find, for others benefit.

speaking of OOBE baby, here are some related handy links :

Out-of-Box-Experience Wizard Stops Responding or Requires Computer Restart After You Change the Computer Name

How To Install / Uninstall OOBE

[azzu]

nice info

[Harvik780]

for me it never takes more than 5 minutes and i have a quite old system

[casanova]

Nice info. It doesnt take much time for me though

[rakeshishere]

Good Info ..Will check and then reply