IISRESET /reboot returns error?

General question for something I just bumped into.

Issuing "IISRESET /REBOOT" on either a Windows 7 Enterprise or Professional box from the command window (running as Administrator) yields the following on both.

'Attempting reboot...
Reboot attempt failed.
Not implemented (2147500033, 80004001)'

This appears to be a missing component or one that has not been enabled. After looking around on this site and Google I was unable to locate anything definitive.

Any suggestions?

Thanks!

best,

DD