GUEST,watcher mentions Portable Open Office.
The whole PortableApps Suite is worth looking at.
I have been using it since 2006 (Old Thread BLICKY ).
It contains a bunch of applications which can be downloaded and run separately, but are also bundled with a launch menu that allows you to add new applications when available. It is designed to run from a USB stick without anything installed on your computer. That said, I have found it useful kept as a permanent feature on my computer.
The fact that it does not "Install" or add registry entries means you can just copy the lot into a folder, which can be moved to ANY drive, fixed or externally attached to the PC and it will work from where you put it.
Included in the bundle are portable versions of Audacity (Sound recording and editing), the GIMP (Graphic editing and Manipulation), firefox browser, instant messaging, Music/video player and lots more. You can add as many or as few as you wish to use, and if you want to "uninstall" one, you just delete the folder it is in.

Quack!
Geoff the duck