Playing with the Registry

One of the advantages of working for a company like Microsoft is that you get some machines that are disposable – in the sense you can reinstall the operating system anytime you want. This leaves me free to play around with the machine in any way I want. And the registry is one of the first places I mess around with.

Let me tell you up front that this is something that is not advised. The reason? You will be handling something that could screw up everything on your machine big time. Many applications depend on the registry for almost everything.

What you stand to gain though is some fun and a lot of learning. And you’ll also understand and appreciate why you should never mess around with the registry. If you do just what I say and nothing else, everything should be fine. Let me call out right now though, that if something gets screwed, I probably can’t help you and I definitely can’t be held responsible in any way whatsoever. Use this at your own risk. There – now that we’ve got the standard disclaimers and stuff out of the way, let’s get to the actual stuff.

For starters, I’ll take you through a very simple exercise, with a little treat for Vista/Win7 users at the end.

First off, let’s open the registry editor. In case you don’t know how to do that, go to start, click on run and type regedit.exe in the textbox and press enter. If you are a Vista/Win7 user, click on Continue in the UAC prompt. The registry editor should’ve opened up now. You’ll see “My Computer” on the left half with a few folders beneath it. If you click on the folders, they will expand to reveal more inside them. The right half would typically be empty for those of you that have opened the registry for the first time. The folder like thingies are called “Registry Keys”, while those on the right pane are called “Values”. Each value has a name and some data associated with it – the data type helps determine if it is a String (text) or integers (numbers)

Now comes the fun part. Remember, I told you that most programs save their info in the registry? Well, you can pick your favourite (or least favourite) program and mess around with its settings. You might even make the program unusable!
Ok, that wasn’t the simple exercise I was talking about. Here goes. I’ll just list them in steps for easy readability.
1. Expand HKEY_CURRENT_USER (double click on it)
2. Expand Software under HKEY_CURRENT_USER
3. Whoa! Huge list, right? Recognize most of the names? You should – they’re related to the software installed on your machine. Well, scroll down till you see Microsoft and double-click on it.
4. Scroll down this new list to Windows and expand that.
5. Expand Current Version under Windows.

That’s a lot of interesting looking stuff, right? Let’s try something simple. There are three folders under Current Version that are of interest to us right now – the third only if you are using Vista/Win7. These are named Applets, Run and Screensavers.

First, look for Run and click on it once. In the right hand side pane, right-click and choose:
New->String Value
Type whatever name you want for that Value – I’ll name it MagicValue. Now open MagicValue by double clicking on it. In the text field that it shows, type notepad.exe and click OK when you are done. Congrats! You’ve finished your first registry tweak! Now whenever you turn on your machine, a notepad window will pop-up. Irritating, yes, but you can replace it with anything else that you want, for example Outlook. Now some of the more computer-savvy ones might say this can be done through the StartUp folder that Windows provides. You can. What you’ve gained by doing it the registry way though, are two things: Firstly, you have now learnt a little more about the registry. Secondly, see if you can find a way of removing this application without deleting the registry key! You can’t see it anywhere in the startup folder! (There is another place though, but I’ll save that for another blog, another day)

Now you know how to annoy your friends with some weird programs that start every time they start their machine…
How do you remove it? Well, just delete this MagicValue that you created. Windows will say “this might affect some programs” or some similar rot. Well, we were the ones who created it, so deleting it should be fine. Go ahead and delete it.

That was it with Run. Now for the next part – applets. Before that, close regedit and reopen it. Notice that regedit opens in the same place you were just before you closed it? Nice, right? Let’s try to figure out how that is done. First, expand Applets. Wow, there’s paint. And wordpad. And I’ll be doggone, there’s regedit! Click on the Regedit key once. See something on the right hand side? Some value called LastKey? Read the value next to its name – heck, it is the same key that regedit opened in! That’s how it opened the registry to the same place you were in before you closed it! Delete LastKey. Ignore any warning from Windows if you get one. Close and reopen regedit – let’s see what happens. Whoa! Did you see that? Regedit still managed to open in the same place – and can you see why? The value is back! Well, those guys must be saving the value when regedit exits, so…

Now, here’s the ‘treat’ for you Vista/Win7 guys. I’m not sure which flavours of Vista this will work on, but have you noticed that for some reason, you can’t customize the screen saver? If you’ve never tried it, minimize regedit, right click on the desktop, and choose Personalize. Choose screensavers from the window and choose aurora or bubbles or something else. Try to modify them – you can’t. Now maximize the registry again. Expand the Screensavers key that comes under Current Version. (The same place where you found Applets and Run earlier) Click once on whatever screensaver you want to modify. Mess around with the data of the values (the stuff on the right hand pane) to your heart’s content. I’m not going to tell you what each one stands for – change them all and figure out what they mean or stand for. Let’s see if you can customize any of them to something you like!

That’s all for now folks. Next time, I’ll teach you a neat little trick – how to make Solitaire start every time your boss tries to start Outlook or Excel or whatever! Stay tuned!

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