Can I put regular programs like avast onto a u3 usb device?

All depends on the application. Some apps use the registry when installing and therefore can't really be installed on a USB and then used on a different PC. However there is a newish USB drive made by Sandisk and has a U3 application function that allows ''some'' programs to to be installed and then used on other PC's. This is because the U3 function does a temporary write to the registry on the computer.

Check them out at www.sandisk.com/

Hope this helps, good luck.

Can I put regular programs like avast onto a u3 usb device?suzuki

Definitely you can add the INSTALLER file (which is usually in .exe). Sure you can copy the avast folder, but if you want to transfer is this way to another computer, I have my doubts that it will work. There are too many registry entries not copied and the program can just malfunction.

The best way is to copy a installer file into your USB device.

Can I put regular programs like avast onto a u3 usb device?virus

It is tricky, but you could do it.
you can put the installer program on it and install from the usb drive
There's a version of Avast specifically for u3 drives:

http://www.avast.com/eng/avast-u3.html

Installing a normal program that runs when Windows boots (antivirus, firewall, etc.) on a flash drive (u3 or otherwise) isn't something I would recommend unless you know that drive will /always/ be plugged in when the computer is on. (If you want programs to be used on multiple computers then you want U3 specific stuff.)