When ever I download zipped files, I can not extract the data from them. Windows Security Manager pops up together with Norton Antivirus to say that the file contains a virus and that the the file may be blocked. This happens with every zipped file that I have downloaded. Am I to assume that each and every file I have tried does actually contain a virus, or is this an example of Norton/Windows being over cautious. I have tried unblocking the file in Properties but it the option simply is not available to me. I am running Windows XP Home with Norton Antivirus 2005