Deductions & credits

1)...he may have had another virus software set running.
2)  One other thing to try instead of uninstalling.  Some people may have their virus checker set at it's highest setting.  I don't know where they would be for you, but check your virus scanner setting to see if you can reduce it to a lower level somewhere in it  first. and then see what happens.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*