Welcome to the avast forums Uninstall McAfee.
You Can have Program like Malware bytes or Super Antispyware Along with Avast!
Clash of the antivirus apps article" http://www.smartcomputing.com/editorial/article.asp?article=articles/2003/s1407/38s07/38s07.asp
Links
Malware bytes: http://www.malwarebytes.org/
Superantispyware: http://www.superantispyware.com/