Open regedit and navigate to:
Once there find the folder named after the program you installed and delete it. If you can't find the folder, it could be one of the first ones with all the numbers and letters. If that is the case go thru those and see if you can find the program name inside one of those folders.
Hope that helps.
-UV Reactive Acrylic Mid-Size Case
-AMD Athlon XP \"Barton\" 3200+ 400MHz
-Cooler Master Aero7+
-Asus A7N8X-E Deluxe Mobo
-nVidia GeForce FX 5700 128MB
-2x Kingston HyperX 512MB PC3200
-2x 200GB WD 7200 8MB SATA
-2x 12\" UV Cold Cathodes
-5x 80MM 4UV LED Blue UV-Reactive Fans
P3 750MHz, 512MB, CD-RW/DVD Combo, 15.1\" TFT, 20GB HD, 32MB integrated video