Running Programs on a Custom Flash Drive
What are Portable Applications
A Portable Application is a software program that could be run from any removable storage device like USB Flash Drive, Flash cards and Flash Disks. A portable Application does not leave any files on host computer and does not write anything to windows registry. Instead of that the portable applications save its settings in INI file in the located in its directory.Here is a list of FREE applications that can be installed on a USB flash drive.
How To Install Portable Application
Most of the Portable Application comes in zip or exe format. Copy the application you want to install on you USB drive. Double-click the file to start the installation. Follow the on-screen prompts and select the location you'd like to install to. Within the directory you select, an [AppName]Portable directory will be created containing the portable app.
Using Portable Application
Browse To directory where you have installed portable application and click on the icon in the [AppName]Portable directory, double-click the [AppName]Portable.exe file. Then, just use the app as you'd use the regular version.
When you're done, close all your portable applications. Then select the 'Safely remove [device]' option from the icon in the system tray. If you remove the drive while it is in use, you could corrupt your apps and lose your data.
Upgrading a Portable Application
For upgrades, you should select the parent directory of the [AppName]Portable directory in which the app is currently installed. For example, if the app is within X:\PortableApps\[AppName]Portable, you'd want to select the X:\PortableApps directory in the Browse Folder window. After clicking OK, it should show X:\PortableApps\[AppName]Portable. All of your current settings and data will be preserved.Be sure to review our 200+ custom flash drives ready for your next promotion. Provide them something memorable and useful. USB flash drives with your logo and free applications that help them to their jobs.
Source: - http://portableapps.com/support/portable_app#installing