I'm not sure why exactly this has started up, but I seem to be getting an error with avast! 4.7 Home Version when I try to have it quick-scan a file or even start up the main Antivirus scanner. When it tries to quick-scan, it takes a while to initialize the engine, only to come up with an error that it cannot create a file when it already exists, and then exits out. As for the Antivirus scanner, it brings up slightly the same thing. I attached a picture of what it shows after it tries to startup. "183 = Cannot create a file when that file already exists." I searched for that in the forum but I couldn't really isolate why this was brought up or how to fix it. Sorry if it was addresses elsewhere and I just didn't realize it.
