Join Mike Meyers for an in-depth discussion in this video What is the registry?, part of CompTIA A+ (220-902) Cert Prep: 3 Windows Basics.
- The Registry is this great mystery inside of every computer, but if you think about it for a minute, it really makes a lot of sense. If you go back a million years, or at least back to versions of Windows, like Windows 95, everything you did within Windows was configured through some form of text file, usually with the extension INI. In fact, Linux users are like, well yeah, that's how everything works, Mike, and there's nothing wrong with using all these different initialization files to configure things, but Microsoft felt a long time ago that life would be a lot easier if instead of using a gazillion text files that were all over the place, if we had one common storage area.
That common storage area is the Registry. The Registry is not a text file, it's a database, and you have to have a special reader to be able to read, edit, or do anything you want to this particular database. But, the important thing to appreciate with the Registry is that pretty much everything that is Windows, is in the Registry somewhere. Registries can be massive files depending on how much stuff you have loaded in there, and pretty much, anytime you go to control panel, change a screensaver, add a piece of software, anything you do, one of the main things you're doing is updating the Registry.
So, we're messing with the Registry all the time. However, there are times where you're gonna have to go in to the Registry manually. Now, the A Plus does not expect you to become an expert at Registry manipulation. It does expect you, that if there is a problem where the Registry has to be accessed manually, that you understand it well enough, so if somebody's telling you to put in some bizarre command, or something like that, that you can open the Registry, do it the right way, create a backup, and make it work. So, let's dive in to the Registry.
So, to get to the Registry, all we need to do is type in REGEDIT. That's the reg edit, and this is actually the Registry editor itself. Remember, the Registry is not a text file, it's just like you need Microsoft Word to edit a word document, it's its own particular format, and you have to use the Registry editor. Now, there's a long shot, but there use to be another program called REGEDT32. You see how I've got it typed there? REGEDT32, and back in the old days, there was actually two different ways to run it.
So, you can either type in REGEDIT or REGEDT32, and either one of these will get you to the Registry editor. The big thing you need to keep in mind with the Registry editor is that you've got these five root keys. Okay, HKEY_CLASSES_ROOT is basically defines everything that is your computer. Every type of file, every type of data structure. It's monstrous, and it's not a place we have to go to very often, but that's what it handles. HKEY_CURRENT_USER is all the information about the currently logged in user.
So, everything from my screensaver to what my background looks like. Anything that I might have setup, that's gonna be showing up here under HKEY_CURRENT_USER. HKEY_LOCAL_MACHINE is information about this particular computer. What software's installed. What hardware's installed. How the security is set up. Pretty much everything that is this computer is under HKEY_LOCAL_MACHINE. Now, HKEY_USERS is nothing more than a list of all the different accounts that are currently on this computer.
They're kinda encoded, and one of these is actually me right up here in HKEY_CURRENT_USER. So, if I were to break one of these down, you can actually see it looks similar to what you're seeing in HKEY_CURRENT_USER because it just grabs one of these, and makes that HKEY_CURRENT_USER. The HKEY_CURRENT_CONFIG is nothing more than the current setup of the system, and that's like any particular issues with software, or hardware to be set up at any given moment. Okay? Make sure you know these five root keys for the A Plus exam.
Now, the one thing we like to do more than anything else with the Registry is that we will make subtle changes. A lot of times, it's not changes that we actually understand, but it's because someone tells us to. Now, here's a very famous one. I'm gonna march you through it. You go to HKEY_LOCAL_MACHINE, and then, you go to SOFTWARE. Then, you go to Microsoft. You go down to Windows. Then, you go to CurrentVersion.
Underneath here are two little settings that are really kinda famous. It's called Run, and RunOnce. Run is the standard place for most auto starting programs to appear. So, if you ever wanna actually take something offline, you would actually go to this particular location, and you could delete it. Now, the other thing I wanna show you, and that's on the A Plus, is that sometimes you do have to edit the Registry. So, one really important thing we always do before we edit the Registry is we make a backup.
So, right now, you'll see that I've got this Run highlighted. So, what I'm gonna do is I'm gonna export just this piece. I'm just gonna call it fred. And, what I've done is I've taken just this one piece of the Registry, and I've got a back up copy of it. So, if I wanna delete anything outta here, so like here, I just can arbitrary delete a couple of things and so, I've deleted two things that auto start.
Now, if I were to suddenly discover that oh, I kinda wanted those. If I wanted to bring them back, all I would need to do is I can right click, and then, I can click on merge. You see that? So, any time I make a backup, it will, by the way, all backups have the last name REG, and I can bring it all back just by hitting merge. Ta-da. There they are. So, that's the big stuff to remember about a Registry.
CompTIA does not expect you to become a Registry genius. Nobody knows the entire Registry, but it does expect you to know how to access a registry, how to make modifications to Registry settings, how to export, and how to recover exports in case you need them. That's about it. (upbeat music)
Part 3 covers the Windows operating system: all the basics you need to know to troubleshoot the inside of a PC. Author and CompTIA expert Mike Meyers takes a look under the hood at the processes, services, and tasks and provides an overview of user management, which is one of the foundations of Windows security. In Chapter 3, you'll learn some techniques for maintaining and optimizing the performances of Windows, including backup and restore procedures. Every lesson maps to a question in the critical Windows domain—an estimated 30% of the exam.
Details about the certification and the exam blueprints can be found at https://certification.comptia.org/certifications/a.
- What is the Windows registry?
- Understanding the boot process
- Using the Windows 8 Task Manager
- Creating and managing users
- Working in the Microsoft Management Console
- Installing and uninstalling programs
- Backing up and restoring Windows