What seems to be a new and improved version of Antivir will change your proxy server so that even if you do remove it as previously directed it will reload with your first IE logon. Updated directions for easy removal are
here.
The loading of Malwarebytes can be done @
FILEHIPPO for free. Two other free packages I recomend from this site are CCleaner and SuperAntiSpyware. All are easy to load and free. Unlike many other packages, the free versions will fix any problems that are found. The Firefox browser can also be downloaded at FILEHIPPO. If you like the packages, you may purchase the complete/deluxe version.
Remember, never, ever pay a site to remove a virus that you were unexpectedly warned that you have. The warning itself is a virus and you are giving your credit card number to thieves.