If you get an error while trying to open the webpage, for instance, http://www.google.com you might get the following error:
“The page cannot be displayed”
followed by http://www.google.com turning into the http:///?%www.google.com for instance.
To resolve this, take a look in C:\windows\system32\drivers\etc\ hosts file.
Make sure that there is no other line than “127.0.0.1 Localhost”… if you’ve been infected by a spyware/malware, it may have change this file so when you type in google.com or gmail.com it redirects you somewhere else.
You should scan your PC using THIS guide, and take the time to “repair” your network connection by right clicking your local network connection(in network connections), than select repair. It will clean the arp table as well as the DNS cache.