Hi dog199200
. . . and Welcome to the Tech Support Forums.
Could you open a new thread for your question over in the Vista forums? Thanks! (It's more polite to open your own thread, because members often receive emails for their threads, & we don't want to flood their inboxes with other members repairs).
In the meantime, though, make sure that Vista isn't set to automatically restart on error. Go to Start - Control Panel - System and Maintenance - System - Advanced System Settings - Settings - Startup & Recovery - uncheck the box "automatically restart" & then click OK. This should let you view the error that is likely occurring as you system attempts to shutdown.
You can also view these and other possible errors using Event Viewer. The fast way: right-click on "Computer" in the Start Menu, and select "Manage" - then select Event Viewer from the list of tools. For an indepth look at using Vista's Event Viewer, see this article ---
http://www.petri.co.il/vista-event-viewer.htm --- Event Viewer is a handy tool for tracking such errors as yours, which can be due to many different causes.
Best of luck!
. . . Gary