You could always use 'system restore' and restore the PC to a previous state before the problem started.
I would go with the command prompt that licquorice has suggested. Something is running and changing your DNS and this should show what it is.
Have you at anytime installed any programs or OpendDNS to cover what Internet Browsing you are doing?
Also proxy servers can change the DNS settings to point to LocalHost (127.0.0.1). Make sure that you are not running any browser addons which may be intercepting your web browsing.
Cant seem to type what you've suggested, will this work? netstat -ano/find ":53"
I cant find the symbol you have between ano and find?