Avast antivirus detected c:/program files/Avast antivirus as a virus?

Almost any file on a Windows Computer can be infected by a virus so it is possible that one way or another that specific file was infected. But it could also be an error, because some anti-viruses are known to give "false alarms" from time to time, so In this case It is probably an error, unless you go on unsafe websites then yes I would be worried.