The CodeFromThe70s blog has a tutorial for backing up your current installation of Windows XP to a virtual machine that you can access at any time from your fresh installation of Windows, potentially easing the process of a fresh install.

Obviously for your most used programs you don't want to start up a virtual machine every time you want to get something done, but for those once-in-a-blue-moon efforts, moving to the virtual machine may be a lot quicker than hunting for and installing the program you need.