Mac the Knife
As others have suggested I would avoid editing the registry directly unless you really know what you're doing.
Instead there are various pieces of software that'll let you manage the programs that start with Windows. The neat thing is that they often also pull together the registry run entries along with the Startup group from the Program Files menu so that you can see them all in one list.
For example,
System Mechanic is one - that also gives you the option to simply disable rather than delete various startup entries so that you can restore them later if you run into any problems.