How to make application or software run in extranal device?

www.portableapps.com answer to all your needs buddy ;)

ive heard there are softwares that can be run from external drives.. for example you can run windows xp from a pen drive. you just need a few tools to do that. also you can have may software's like portable firefox, anti virus like clamwin which is portable too. for example you can go to www.portableapps.com and download your desired portable app and run it through your external drive

Yes, Cruzer by San Disk can have programs installed and run directly on it. I tried it with a couple of games, and it worked Ok. You just install it like you would any other program, but make sure you put it into the flash drive, and not your regular hard drive.

Most USB sticks and such don't allow programs to be run from it. I saw some new USB device being able to do that though it was called like "Cruzer" and it wasn't even that expensive. ;)