How can you get rid of a virus that pops up at random and deletes a handful of files?

The virus can escape from antivirus,as you saw,it infected on her computer under protection of antivirus,what's worse,it cannot deleted by antivirus.In this case,I propose manual removal.By the way,the virus didn't delete her files or folders on her computer,it just hided them which means thay can be restored.