Don't know How To Do SFC
How do I do SFC? Thanks. Maybe I should also mention that I tried to download and install Avast again but when I click the exe file the next window asks me what program I want to use to install the program. That I don't know. And every time I send the exe file to the recycle bin, even if I empty the recycle bin, every time I open Firefox, the exe file reappears on my desktop. I can't get rid of it.