If you use multiple computers, you most likely have a USB drive. However, you may want to use the same software on each one. If so, check out The Portable Freeware Collection.
What is portable freeware?
In simplest terms, it’s freeware you can run off a USB memory stick, and hop from computer to computer with. Usually, all the settings are stored in the folder the application is in. Most of them don’t require installation.
You don’t even need to use a USB stick. Some people just like to know where their settings are kept. And of course, if you need to format your computer, you can just put it on a floppy or USB drive and it’ll be ready and waiting for you when you’re ready. No re-installing, no re-configuring.