I have failed to delete a file detected by Avast

Hi Experts,
I have failed to delete a file detected by Avast. While deleting it says
Operation did not complete successfully because the file contains a virus.
What does it mean by the message mentioned above? Is there any problem with my Avast?
Please suggest me to solve this problem.
Thanks in advance.

C:windows.explorer.exe
Operation did not complete because the file contain a virus.
OK
