What is the Windows Registry? Think of it as the "brains" of your Windows installation. Specifically, it's a giant warehouse, a single, easy-to-access, hierarchical database that stores each of your system's settings (and a ton of additional information). Without it, your Windows computer is little more than a paperweight. Mess it up, and you have a big problem on your hands. However, if you understand what you're doing with the Registry, you can tweak pretty much any Windows parameter you wish.

We've listed our favorite Registry tips and tweaks below. Don't forget: You likely won't see the effects of your fiddling until you reset the computer. Also, read "6 Registry Hacks to Make Your PC Faster" for more suggestions.

Back Up the Registry

Before you start playing around in the Registry, you must back up your system's precious information. We have to warn you once more: Mess up your Registry tweaking, and you might not even be able to boot into Windows to correct things.

To back up the Registry the easy way, simply open Control Panel, click System, and then click System protection on the left sidebar. Click the big Create button to have Windows walk you through the straightforward process of creating a System Restore Point--it's as easy as that.

You can also fire up the Registry Editor--the tool you'll be using to make your tweaks--by typing regedit into the 'Search Programs and Files' box, which you can find by clicking the Start button. Once you're in, right-click Computer and select Export, which will dump all of your Registry settings as one giant, importable .reg file.

Add Copy/Move Menus to Windows Explorer

If drag-and-drop has never really been your thing, you can manage files more effectively by editing the Registry to add new 'Copy to' and 'Move to' options within the standard Windows Explorer right-click context menu. Clicking either new menu item will pull up a fresh listing of your drives and folders, and you need only choose the folder to which you want the selected files to go.

In the Registry Editor, navigate down to the following key: HKEY_CLASSES_ROOT\AllFilesystemObjects\shellex\ContextMenuHandlers. Once there, right-click the ContextMenuHandlers key and select New, Key; call the key Copy to. Double-click the (Default) value in the window on the right and enter {C2FBB630-2971-11D1-A18C-00C04FD75D13} for its data.

To create the 'Move to' command, perform the same steps (but call the key Move to) and use {C2FBB631-2971-11D1-A18C-00C04FD75D13} for the value data.

Turn Off Aero Snap

In Windows' Aero environment, windows snap to the sides of the screen by default. But what if you just want to drag windows near the edge of the screen without letting the operating system take control of their size and placement? Don't turn off Aero entirely: Just turn off the Aero Snap function via the Windows Registry.

Navigate to the following key: HKEY_CURRENT_ USER\Control Panel\Desktop. Once there, look for the value called WindowArrangementActive. By default, the value data is set to 1. Double-click the value and change it to 0, and your windows will Aero Snap no more.

Tweak Thumbnail Preview on Mouse-Over

Roll your mouse over an icon on the taskbar and wait a few fractions of a second, and you'll see a thumbnail preview of the exact contents of the corresponding window. Neat, huh? But you're impatient: You want your thumbnail to pop up the second you hover the pointer over the icon. As luck might have it, the Windows Registry offers a way to tweak this delay time.

In the Registry Editor, look for the following key: HKEY_CURRENT_USER\Software\Microsoft\Windows\ CurrentVersion\Explorer\Advanced. Right-click anywhere within the sidebar on the right, and select New, DWORD. Enter ExtendedUIHoverTime as the name. Double-click on your new value and replace the 0 with a 1, and change the Base to Decimal.

Change Your Name in Windows

Here's a fun one. When you first install Windows, it asks you to tell Microsoft your name, your organization's name (if one exists), and the name you want to give your system. The problem? You can change the system's name all you want via Control Panel, but you can't easily change the name that you gave at installation time--or, for that matter, the registered name of someone who might have owned the system previously.

To fix this, navigate to the following key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion. You'll see a variety of values on the right side of the screen. Double-click the one called RegisteredOwner to change it to whatever witty name you can think of.

Disable Windows Update's Automatic Restart

Windows Update is one of the best tools your system has. It's also one of the most annoying tools, as it can frequently download and install updates on your behalf. Although that's great for security, the problem is that the installation routine sometimes pushes an automatic computer restart once it's done. If you aren't paying attention (or if you're busy goofing off with your friends in a game, for example), there goes your session.

Disable Windows' post-update automatic restart by navigating to the following key in the Registry: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows. Once there, right-click the Windows key and select the option to create a new key. Enter WindowsUpdate for the name. Repeat the process for the WindowsUpdate key, but create a new key called AU. Your hierarchy should now look like this: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU.

Click the AU key, and then right-click in the sidebar window on the right and create a new DWORD. Enter NoAutoRebootWithLoggedOnUsers as the name for the DWORD, and then double-click it and change its value from 0 to 1.

Blue-Screen Your PC at Will

What's that? You actually want to crash your Windows 7 system and send it to a Blue Screen of Death? It's your call whether this neat little trick is a useful party gimmick or a great way to fake computer disaster if you're trying to procrastinate on your work. Either way, after you've applied this little tweak, holding down the right Ctrl key and pressing Scroll Lock twice will send your system spiraling.

Navigate over to the following Registry key (if you're using a USB keyboard): HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\kbdhid\Parameters. Right-click the sidebar on the right and create a new DWORD with CrashOnCtrlScroll as the name. Double-click the value and change the 0 to a 1. And then put on your crash helmet.

Hide Unused Control Panel Items

Don't you think that Windows' Control Panel offers a lot of options that you'll probably never, you know, control? When was the last time you needed to update your settings in Credential Manager? Or Phone and Modem? Or Windows CardSpace? Unfortunately, the Control Panel isn't like a Windows Explorer window--you can't just move and delete items. Once again, turn to the Windows Registry for help.

Navigate over to the following key: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer. If you don’t see an Explorer key in the Policies key, create it. Within the Explorer key, right-click within the right-most window and create a new DWORD called DisallowCpl, and set its value to 1 instead of 0 by double-clicking on it and changing the digit.

Next, right-click on the Explorer key and create a new key called DisallowCpl. As usual, ignore the period. Select your new key and right-click on the right-most window once again. This time, you’ll be using your right-click menu to create string values. For every Control Panel icon you want to hide, you’ll need to create a series of string values in numerical order: e.g. hiding two icons means that you’ll need to create a “1” and a “2” string value. Your numbers must be sequential for this to work.

Each string value’s data (which you set by double-clicking on the value itself) should be identical to the Control Panel element you want to hide (e.g. Programs and Features or Action Center).

Hide the Web Search Prompt

Double-click a file that Windows doesn't recognize, and you'll be treated to Old Reliable: the annoying window that asks whether you want to search the Web to find a program that can open the file in question. Seriously, does anybody use this feature? We sure don't, and we're quite happy to see that a simple Registry tweak can forever eliminate this screen. In its place comes the second option on the now-removed window, a list of programs that you can use to try to open the mysterious file.

Go find this key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer. Once there, create a new DWORD by right-clicking the rightmost window. Name this DWORD NoInternetOpenWith and double-click it to assign it a value of 1.

Play a Prank on Your Fellow PC Users

Share your laptop or desktop with other people? Want to give your friends and loved ones a polite little message about how they should use your system, whenever they fire it up? Feel like pulling an awesome prank on someone else's PC? A little Registry tweak will add a pop-up message that a user must click through before he or she can log on to your machine.

Navigate over to the following key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\Policies\System. From there, double-click the legalnoticecaption value. Whatever you enter as data will serve as the header for your message. Any data you enter after double-clicking the legalnoticetext value will show up in your pop-up message. Make it good!