"[Program] contained an virus and was deleted" error when trying to download

Moving this post over to viruses & worms…
Hoping someone can help… I’ve tried dowloading the Avast 2014 Free Anti-virus program both through C-Net & directly from avast but every time it nears the completion of the download, Windows throws up a message that the program contained a virus & was deleted. I tried downloading the AvastClear program but I’m getting the same message. What should I do?
I’m still running Windows Vista, currently with no AntiVirus protection, since I uninstalled the previously installed Avast version on here (it was V4.8 LOL) because every time I tried to run the update routine, it said it was already up to date.
I am getting the “Avast contained a virus and was deleted” error whether I save the file or just try to run it. And get the same message when trying to download anything. I just tried to download AVG Free & I’m getting the same message, that the program contained a virus & was deleted.

Can you attach a screenshot?

Follow this guide and attach the logs (Malwarebytes, OTL, aswMBR) :http://forum.avast.com/index.php?topic=53253.0
aswMBR is not compatible with Windows 8 yet.

If you cannot download anything try to download them from another computer.

Hi you may need to download this using another computer

Please download Farbar Recovery Scan Tool and save it to your Desktop.

Note: You need to run the version compatible with your system. If you are not sure which version applies to your system download both of them and try to run them. Only one of them will run on your system, that will be the right version.

[*]Right click to run as administrator (XP users click run after receipt of Windows Security Warning - Open File). When the tool opens click Yes to disclaimer.
[*]Press Scan button.
[*]It will produce a log called FRST.txt in the same directory the tool is run from.
[*]Please copy and paste log back here.
[*]The first time the tool is run it generates another log (Addition.txt - also located in the same directory as FRST.exe/FRST64.exe). Please also paste that along with the FRST.txt into your reply.