Before you begin messing with your system
The registry is no child’s play
Modifying the registry can cause serious problems that may require you to reinstall your operating system. I cannot guarantee that problems resulting from modifications to the registry can be solved nor do I provide technical support for such issues if they occur. Use the information provided at your own risk.
Before you dig in
Tweaking isn’t for everyone. If you’re using XP or Windows 2000 and you like it the way it is, leave things alone. Some changes are hard to undo, so don’t make needless changes to your operating system. Likewise, weigh each suggestion against the likely benefit you’ll gain. Don’t tear apart a working operating system or subsystem unless you believe the results are truly worth it.
Anyway, before you do any significant tweaking work on any operating system, always make a full backup. You need to be able to restore things to the way they were before, if a change doesn’t work out the way you intended.
In Windows XP, it’s also a good idea to make a “Restore Point” before each and every change. System Restore can roll back many minor system changes without requiring you to restore your full backup.
Also, it makes no sense to try to tune and tweak an operating system that’s fundamentally incomplete or broken. I suggest to always try to use a clean installation of the OS, and never rely on upgrades or other dubious installations. You should always check to ensure all your hardware is set up and running properly. In addition, use Windows Update to download and install all current patches and driver updates.
Currently, no “undo” function exists for deletions made within the Windows XP registry. The registry editor (Regedit.exe) prompts the user to confirm the deletions. When a registry key is being deleted, the message does not include the name of the key being deleted. Check your selection carefully before proceeding with any deletion.
By the way, The Windows Registry Guide, formerly RegEdit.com, provides an extensive range of registry tweaks, tricks & hacks for optimizing, enhancing and securing the Windows operating system. They offer hundreds of online tips and a cool offline .CHM file to download.
What is the Registry?
The Registry in Windows Operating Systems is a central hierarchical database used in Microsoft Windows 9x, Windows CE, Windows NT, and Windows 2000 used to store information necessary to configure the system for one or more users, applications and hardware devices.
The Registry contains information that Windows continually references during operation, such as profiles for each user, the applications installed on the computer and the types of documents that each can create, property sheet settings for folders and application icons, what hardware exists on the system, and which ports are being used.
The Registry replaces most of the text-based .ini files used in Windows 3.x and MS-DOS configuration files, such as the Autoexec.bat and Config.sys. Although the Registry is common to several Windows platforms, there are some differences among them.
Registry data is stored in binary files. Administrators can modify the registry by using Registry Editor (Regedit.exe or Regedt32.exe) from the Run command.
(Windows 2000 Regedit screenshot)
(Windows 2000 Regedt32 screenshot)
If you use Registry Editor incorrectly, you can cause serious problems that may require you to reinstall your operating system. Microsoft (and I) does not guarantee that problems that you cause by using Registry Editor incorrectly can be resolved. Use Registry Editor at your own risk.
For additional information about the differences between Regedit.exe and Regedt32.exe in Windows NT and Windows 2000 go to 141377
In Windows XP and in Windows Server 2003, REGEDT32 (which was native to Windows NT and 2000) and REGEDIT (which was native to Win9X) were replaced by a new version of REGEDIT which combines features from both tools. In Windows XP, the new version is marked as version 5.1.2600.0 while the W2K one was v 5.0.2134.1. In Windows Server 2003 the version number is 5.2.3790.0. Try typing REGEDT32 or REGEDIT and you’ll find the same tool pops up. You’ll like it better than you liked the old tool (and yes, it has the PERMISSIONS feature!).
(Windows Server 2003 Regedit screenshot)
Editing the Registry
These tips may contain information about editing the registry. You should not edit your registry unless it is absolutely necessary. If there is an error in your registry, your computer may not function properly. If this happens, you can restore the registry to the same version you were using when you last successfully started your computer. Incorrectly editing the registry may severely damage your system. Before making changes to the registry, you should back up any valued data on your computer.
The following list provides some best practices for using the registry and Registry Editor safely:
- Before making changes to the registry, make a backup copy. You can back up the registry by using a program such as Backup. After you make changes to the registry, create an Automated System Recovery (ASR) disk. For troubleshooting purposes, keep a list of the changes you make to the registry.
- Do not replace the Windows registry with the registry of another version of the Windows or Windows NT operating systems.
- Use tools and programs other than Registry Editor to edit the registry. Incorrectly editing the registry may severely damage your system. You should use tools and programs that provide safer methods for editing the registry.
- Never leave Registry Editor running unattended.
If the key or value you’re about to edit has no critical influence on the OS, you can simply save the portion of registry that you’re working on, and avoid backing up the whole system state.
To export a registry key to a hive file:
- Open Registry Editor.
- Select the key that you want to save as a file.
- On the File menu, click Export.
- In the Export Registry File dialog box, in Save in, click the drive, folder, or network computer and folder where you want to save the hive.
- In File name, enter a name for the hive.
- In Save as type, click Registry Hive Files.
- Click Save.
You must be logged on as an administrator or a member of the Administrators group in order to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure.
You can use a text editor like Notepad to work with the registry files you create by exporting.
You can save registry files in the Windows format, in the format used in Windows 95, Windows 98, and Windows NT 4.0, as binary hive files, or as text files. Registry files are saved with .reg extensions, and text files are saved with .txt extensions.
In Windows Explorer, double-clicking a file with the .reg extension imports the file into the computer’s registry.
If you want, you can later import the saved registry file back to your registry (or to another computer running the same OS).
To import a registry key from a hive file:
- Open Registry Editor.
- Select the keys in which you want to restore the hive.
- On the File menu, click Import.
- In Look in, select the drive, folder, or network computer and folder in which the hive is located.
- In Files of type, click Registry Hive Files.
- Select the correct file name for the hive.
- Click Open.
How to undo the changes made to the Registry?
If the changes you made in the registry caused your computer to fail, BSOD or stop responding, and you cannot restart it as usual, you could use the Last Known Good in Windows 2000/XP/2003 configuration as long as you did NOT log on AFTER you made the changes.
For example, if you made some changes to the registry, such as disabling a service or a driver, and these changes cause your system to become unstable, do NOT try to restart and log on to fix the problems! Instead, restart your computer into Safe Mode in Windows 2000/XP/2003 and see if you can fix it up.
Do NOT attempt to boot normally and log on, because if you do so, the previous Last Known Good configuration (the one that was created BEFORE you made the bad changes) will be overwritten by the bad registry, and you will not be able to revert back to the previous configuration.
So if you still can’t fix things up, shut your computer down and try Last Known Good configuration.
To restore your registry to it’s last configuration follow these steps:
- Restart your computer.
- When you see the message Please select the operating system to start, press F8.
- Use the arrow keys to highlight Last Known Good Configuration, and then press ENTER.
- NUM LOCK must be off before the arrow keys on the numeric keypad will function.
- Use the arrow keys to highlight an operating system, and then press ENTER.
Important note: Choosing Last Known Good Configuration provides a way to recover from problems such as a newly added driver that may be incorrect for your hardware. It does not solve problems caused by corrupted or missing drivers or files.
When you choose Last Known Good Configuration, Windows restores information in registry key HKLMSystemCurrentControlSet only. Any changes you have made in other registry keys remain.