You may well have a virus that is stopping other software from being installed.
Where are you downloading from? Please give the URL (web address) that is used.
Does the message about virus scan failed name your own antivirus software?
I tried to download from IE and Chrome.
"Anti-virus software failed unexpectedly while scanning this file" it does not name any antivirus software
http://http://get.adobe.com/reader/download/?installer=Reader_10.1.4_English_for_Windows&o s=Vista&browser_type=KHTML&browser_dist=Chrome&d=McAfee_Security_Scan_Plus_Chrome_Browser& dualoffer=false shown on Chrome.
http://http://get.adobe.com/reader/download/?installer=Reader_10.1.4_English_for_Windows&o s=Vista&browser_type=MSIE&browser_dist=OEM&dualoffer=true&chromedefault=false&d=Google_Too lbar_7.4&d=Google_Chrome_22.0_IE_Browser shows for IE
Thank you; tried the link and received the same failed message. I have contacted McAfee; after trouble shooting was told I do not have any viruses on my laptop; tried 2 different administrative logins same results. I contacted Microsoft; they were unable to troubleshoot (could not access system remotely) was told to remove McAfee from laptop and try to install which I did with same results. I lowered the securities on the internet with same result. What am I missing?
Thank you for trying to help me.