You are seeing the effects of a hijackware infection!
NB: If you had no anti-virus application installed or the subscription had expired *when the machine first got infected* and/or your subscription has since expired and/or the machine's not been kept fully-patched at Windows Update, don't waste your time
with any of the below: Format & reinstall Windows. A Repair Install will NOT help!
If these procedures look too complex - and there is no shame in admitting this isn't your cup of tea - take the machine to a local, reputable and independent (i.e., not BigBoxStoreUSA or Geek Squad) computer repair shop.
~Robear Dyer (PA Bear) ~ MS MVP (IE, Mail, Security, Windows & Update Services) since 2002 ~ Disclaimer: MS MVPs neither represent nor work for Microsoft
-- ~Robear Dyer (PA Bear) Microsoft MVP (Windows Client) since October 2002