Just copy and paste the complete folders for the applications from the program files folder to a usb thumb drive or external hard drive. Just make sure that the install.exe and any .exe files that are needed for them to run are included in the folder. For example if you wanted to backup your antivirus program you would have to have the update.exe file(s) and the main program file such as avgfree.exe or whatever it is and any extra options it has that have .exe files such as an email scanner or something.
When you go to install them again, just copy and paste the files from the usb drive to the computer and install them using the install.exe or the programname.exe files they have and you should be good. You may need to register some programs again though when putting them on a new install or a new computer. Free antivirus programs in general should be okay except for ones like avira or avast that have to be registered which is really easy to do. Just go to their website and find the link to register the program and fill in the needed information. They will send you an email then with the key you need to finish the registration.
I'm a computer information systems student and I've done this many times when installing the same programs repeatedly in a lab environment and at home.
