1. Backup your registry file.
2. The problem is in knowing if you want to, or should, remove stuff or not. In other words, will you understand what you are being asked to make a decision about?
FWIW, I have even used REGEDIT to tinker (Click on the Win Start Button, RUN and type regedit). However, I was looking for a specific word to remove some "sticky spyware".
Have fun.