When you say 'my computer will not boot in safe mode', what exactly does that mean? Does the machine not give you the boot options menu? Does it restart? Does it begin to load and then blue screen? Does it just begin to load XP without giving you any selections to choose?
I have never encountered an XP/2K machine that wouldn't boot into safe mode, at least not one that was functioning properly anyway.
I would try one more time to boot into safe mode and try removing the application. To boot into safe mode, power on your computer and just start hammering away on the F8 key, after the machine posts you should be greeted with a screen that gives you the option to boot into safe mode, safe mode w/ networking etc. etc.