On the assumption that you haven't yourself set up a proxy, if a proxy server keeps on being used then a possible cause is that a piece of malware is responsible, or that you have a corrupted user profile.
However you set up a new user profile and copied all your stuff across to it, so it cant be that..
(you did complete the instructions given for doing that didn't you?
It may be best to take a trip over to the Virus and Malware Removal Forum, read the directions and post your log as directed so that a malware removal expert can take a "look" inside your computer and see if malware is present, if so they will provide step by step instructions on how to proceed.
See here for instructions on how to do this:http://forums.whatth...howtopic=106388
Please include a link to this topic here so that they can see what has been going on. Make only one initial post with everything in it you want to include over in Virus and Spyware Removal forum,.... do not make a second post in that forum until you have received a reply from them (they look first for topics with Zero responses and if you follow up your initial post with a second they will assume you are already receiving assistance from someone and may pass your topic by, and go on to help other folks....
To avoid any conflicts you should follow the directions of the malware removal expert and make no other system changes or scans unless instructed by her/him.
We will place your topic here "on hold" so to speak but when your machine has been checked for malware and you receive the "all clear" please then return to this topic here,if you still have other problems(non malware related with it, and we will pick up where we left off.