Task manager fails to terminate postmaster process.

Hi everyone, I'm new to PostgreSQL administration. I hope the people
here will have some ideas to help me out.

My current situation is that I am moving my database across machines
without access to network. It would be possible, but more difficult to
install a network.

I understand that the recommanded way to make a back up is to shut
down the postmaster and related process, then copy the files. This
worked fine on the donor machine. (Windows XP SP2 postgresql 8.0.1)

I grabbed the file to send them to the receiving machine (Win 2000) On
this one, however, I had a problem. The Task Manager does not allow me
to shut off the postmaster process. Specificaly the error message
says:"Unable to terminate process, the requested operation could not
be completed. Access is denied".

My impression is that such an error message wold only happen on system
critical process.

So, what is the problem? Is this the right path to migration? Would
installing the network a be a better solution?

Wondering,

Geoffrey