You are likely infected with some type of FakeAV. Make sure defs are updated and run a full scan in safe mode.
If that doesn't work, try the Power Eraser:
About Symantec Power Eraser
http://www.symantec.com/business/support/index?page=content&id=TECH134803&actp=search&viewlocale=en_US&searchid=1296309271571
If that still doesn't work, download a second opinion malware checker such as Malwarebytes or Hitman Pro. Install and run a scan in safe mode with either one.