It wasn't very long after I installed XP that I was messing around with the registry. I suspect you're probably going to be doing the same thing or else you wouldn't be in this area of the site. Before you make any changes, take the time to read over this section. It's pretty dry reading material, but it might save you from finding yourself with a putty colored box that just sits there doing nothing rather than firing up XP as you would expect.

There are two ways of working with the registry; software based and direct access. The software based method is generally considered to be safe, although a badly behaved piece of software that mangles the registry can make you doubt the wisdom of this statement. Anyone who has used a computer is familiar with the software based method of making changes. Control Panel is an excellent example. Make a change to one of the Control Panel settings and almost assuredly you have initiated a change within the registry. It's just that you are insulated by Control Panel from seeing what went on behind the scenes in the registry.

Directly accessing the registry is far more dangerous. There used to be two versions of Registry Editor, regedit and regedt32, but for XP they have been incorporated in Microsoft Registry Editor Version 5.1. Type either name in the [Run] box and Version 5.1 is what you're going to end up with. The only real disadvantage of not having regedt32 anymore is the lack of read-only mode in Version 5.1, but it just means you need to be careful not to make any unintended changes when browsing through the registry.