Horror Story!! invaded by Proxies!!!

Thank you already for assistance as this one is pure
madness. Using WinXP; was browsing away and within 2-3 min
connection becomes lifeless, usually when going forward.
It took me 5 days to Discover that 'something' is
inserting a proxy, 127.0.0.1 and port 7___ something in
the proxy place box; (tab at bottom of connections)
Before posting here, I have run every public Dangerware
program that commonly turns up in a google search.
(adaware, spybot, webroot etc). No difference, no how
no way. One small clue is this: Had a very old ATT dial-up
network connector and just gave it a remove while I was in
there. I got an hours repreive!! I thought it was
fixed!! That was on Wednesday. Then Mr.Proxy returned and
will show up like clockwork if you go online. I have had
to switch to my laptop for any HTTP work.(over 60 and have
weak eyes) E-Mail is NOT affected and never was. Help!!!
I'm losing sleep Rich