coox:

I would have to agree with Paul here. If you only modify the registry in your area, the worst you'll do is kill your own program.

The best way to do it I have found is to create a key under
HKCU/Software
with the name of your company then you only modify settings inside that key. That way you will never touch the settings of another program.

Then when you get a bit more confident with the registry you can start playing around with HKCR and start adding file associations etc.