As i moved to standardize all of the installers for donationcoder.com, drag&drop robot was the only program that used a different installer, and as such, upgrading to the most recent version may require an extra step or two.
You should uninstall the prior version first (prior to v1.09), and then install the new version. in the future you can just install on top of the current version but because we are changing setup programs, all versions prior to current one should be uninstalled first.
If you have custom configuration files (which you should if you are using the program) they will probably be left alone during the uninstallation, but i highly recommend you back them up manually before uninstalling. they are in a subdir called ConfigFiles.
You will then have to copy them into the newly installed directory ConfigFiles.