It would be helpful to have more information about what you call "so fouled up".
If by "it runs as a service in the system tray" you mean there is an icon in the system tray like a miniature spybot screen with a padlock in it, then that is Teatimer, not the main program, and if your machine has problems then I would
strongly recommend you
don't have Teatimer activated until your other problems are fixed.
You say "when you try to run the program.... it does nothing", and if this is correct and you can't start the main Spybot program from the desktop icon or from the programs menu, then I would uninstall it completely, then download and install a new copy of the current version from one of the sites at
http://www.spybot.info/en/mirrors/index.html. When you install it, make sure you opt to leave both Teatimer and the resident IE browser helper
inactive for the moment, and also to not get the detection updates during the install.
On the other hand, if you can run the existing Spybot main program, put it into Advanced mode, then goto tools/resident and untick both the browser helper and Teatimer boxes. After reboot the Teatimer icon should no longer be in the task bar.
Once you have a running installation of Spybot, use the Search for updates button on the main screen to get the current detection updates.
I would then clean out all of your temporary files and browser caches before starting a Spybot scan.
Spybot can be run from a USB flash drive however I would not recommend doing so where there is an installed version already present on the computer, because it might well produce some conflicting registry entries. I most certainly would not recommend applying immunisation from other than a properly installed Spybot installation.
If you were more specific about your problems a more suitable answer might be possible.
I installed it, it runs as a service in the system tray, but when you try to run the program (to scan or immunize) it does nothing, litteraly, nothing. I tried booting into safe mode (xp pro, sp2) and running it, but that gives me the same results.