Huband computer been hacked can't accesses internet

My husband computer has been hacked. Someone called him saying his computer was runing errors and warnings. They claimed they were with micro soft and would fix it for $250. They said they could fix it by removing vista and putting windows 7 ultimate. He let the person into his computer and they worked on it for hours. This happened 8-27

 

The next day he went to check to see if they were with Micro soft and they never had any record of this action.

 

He put a stop to the payment.

 

Nortons ran a scann 8-28

On 9-3 after midnight someone changed things on his computer

Diagnostics policy service is not running. is what  his computer is saying and preventing him to connect with internet.

Is there such a policy through window.

Also we can not get onto internet.

These so called people have not called to find out why they didn't get a payment or why we are not happy with them.

Never gave a call back number nor support Number.  help

 

He want to know if you heard of Clever PC TuneUp Maestro