Windows 7 - Removing Win7 from non-existant Domain

hello, this is my first post.
We have just been sent a free computer for our office. A Windows 7 HP 32bit.
We can login locally i think to a local user KB_SUF/User (where KB_SUF is the name of the computer)
however whenever the UAC comes up when installing anything, we cannot proceed because it keeps saying
"There are currently no logon servers available to service the logon request"
The thing is they sent us the computer without removing it from the domain
Now I cant install the programs i need to work and it doesnt seem like theres a local admin on this computer.
I tried removing this computer from the domain but it requires going through UAC.
Is there any way to make this computer a Local only PC?

The company that sent us the computer is in another country and they say they can send someone over in 6 months which is longer than i can wait.

Welcome to the forum.

Did they send any DVDs with it or any way that you could take it back to factory settings then start again ?

I don't know enough about Domains to be able to help but was just throwing out an idea, I don't know whether it would work or not.