It sounds like a particular application / service is keeping the computer
awake.
Aspects of Windows Media Player can do this, as can Windows Media Center.
eg disabling this service may help ....
Windows Media Player Network Sharing Service ( WMPNetworkSvc )
"C:\Program Files\Windows Media Player\wmpnetwk.exe"
--
Jon
"Michael Chare" <MunderscoreNEWS.DeleteThis@chareDOTorg.uk> wrote in message
news:g_2dnS0-zJviG3LXnZ2dnUVZ8nqdnZ2d@pipex.net...
> My computer will not go to sleep if I start and then sign on to my normal
> copy of Vista.
>
> Typically either the screen just flashes off and back on again, or the
> screen goes blank but the disc light is fairly active and the machine
> never actaully stops.
>
> If I select the stop button and then "Sleep" instead of entering my
> password when the machine boots then the sleep function works.
>
> I have other copies of Vista (selected via a boot manager) which work
> correctly.
>
> I have tried killing various processes but so far have been unable to
> determine the cause of the problem, I also have re-instated the hibernate
> facility by running some utility that I found..
>
> I have alwys rather liked the sleep function, so if anyone can suggest how
> it can be reinstated I would be grateful.
>
> --
> Michael Chare