Hei.
Prøv det han sier i denne saken: http://answers.microsoft.com/en-us/protect/forum/mse-protect\_start/cannot-scan-error-code-0x8007139f/8a28e699-80f0-4340-9fda-bbde1f87b824
Deretter kan du laste ned dette programmet og kjøre en virus skan: https://www.malwarebytes.org/antimalware/