Unable to turn Network Discovery On

> Hi,
>
> I have searched all over and can't seem to find an answer to my issue. I
> have a Dell XPS Gen4 running Windows Vista Ultimate Edition. When I go
> into
> the Network and Sharing Center the following radio buttons are off -
> network
> discovery, file sharing, public folder sharing, printer sharing, password
> protected sharing, media sharing.
>
> When I try to turn on any of the functions except password protected
> sharing
> I get the following message - "The specified service does not exist as an
> installed service."
>
> I don't have clue why this is happening, but I would sure appreciate any
> help you might have on this one.
>
> I have a laptop running Vista Premium and I had no issues with these
> settings.
>
> I will note that Vista was installed as an upgrade from XP Media Center
> Edition...I don't know if that has anything to do with it or not.
>
> Thanks in advance,
>
> Bill