Safely Clean Your Windows Registry: Step-By-Step Guide (2024)

Estimated reading time: 5 minutes

In this guide, you will learn:

• What is a Windows Registry?
• How to Use the Registry Editor

What is a Windows Registry?

The Windows Registry is a storage place for a large compilation of details about your computer. All activities in your PC when you first started using it until this date are all recorded in your Registry.

Your PC always creates entries but sometimes does not delete them even if they are not in use any more. It will accumulate unused and junk registry entries which can affect the performance of the system.

How to Use the Registry Editor

Think of Registry Editor as your computer's brain – it holds all the secrets to how your system functions. This is where you will clean up the Windows Registry.

BEFORE YOU START: Editing your computer's registry can cause serious errors on your computer. Always create a backup before making any changes.

STEP 1: Open the Registry Editor

1. On your keyboard, press the Windows and R keys at the same time to open the Run window.
2. In the Open field, type regedit, and then press ENTER. The Registry Editor will open in a new window.

   

STEP 2: Create a Registry Backup

Registry keys are important to the functionality of your computer and its installed programs. Accidental removal of an essential registry entry may damage the system of your PC. Having a backup allows you to recover accidentally deleted entries.

1. Click File on the menu bar, and then select Export.

   

2. Choose where you want to save the backup file, and then click Save.

   After saving, the Registry Editor may become unresponsive. It is saving all entries to the backup file and you will need wait for it to be responsive so you can proceed.

   To recover the created back up, choose the option to Import and then open the backup file that you saved.

   See Also

   How to Add, Change, & Delete Keys and Values in the Windows RegistryHow to Fix Broken Registry Items: Visual Guide and Solutions | VaronisHow often should you clean and optimize your registry?How do you remove stubborn registry keys

STEP 3: Clean up Program and Application Registry Entries

Installed applications create many registry keys that are essential for their functionality. It is important to locate and delete entries of uninstalled software if they have not yet been removed before.

1. Double-click the HKEY_CURRENT_USER address to expand the entries under it, and then double-click SOFTWARE. These are sub-keys associated to applications installed on a specific user account.
2. Check the entries and look for applications you know are already uninstalled. Right-click on the specific sub-key, and then select Delete.

   

3. Once done, double-click on SOFTWARE and on HKEY_CURRENT_USER to minimize them.
4. Double-click on HKEY_LOCAL_MACHINE, and then double-click SOFTWARE. These are sub-keys associated to applications installed on all user accounts in the computer.
5. Check the entries and look for applications you know are already uninstalled. Right-click on the specific sub-key, and then select Delete.

   

STEP 4: Clean up Prematurely Removed Software Registry Entries

Manual deletion of applications and programs will only delete the programs and their files, but it will not automatically remove their created registry entries. These entries will stay there until they are removed.

1. Expand HKEY_LOCAL_MACHINE, and navigate to the location HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall.
2. Under the Uninstall key are sub-keys that contain values named UninstallString within them.

3. Check if there are still sub-keys of files or programs that do not exist anymore or verify the path given in the value data of these entries.

   The registry key is invalid if the path is not complete, incorrect, or the UninstallString value does not exist.

   

4. If it is invalid, right-click the sub-key and select Delete.

   

STEP 5: Clean up Invalid Shared DLLs

The Shared DLLs key contains all DLL files that are commonly used by multiple programs and applications. There might be some invalid or corrupted entries that can be removed.

1. Expand HKEY_LOCAL_MACHINE, and navigate to the location HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SharedDLLs.
2. The Shared DLL key contains hundreds of entries with DWORD Values. The name of these entries are the location/path of the file. To check if it is an invalid entry, see if the location/path is correct.
3. You can either correct the path of these entries (if you know it) or delete it.

   

STEP 6: Clean up Startup Items

Startup items are programs that automatically run when you login to your computer. Entries that are invalid can be removed so the computer will not check them anymore during startup.

1. Navigate to the following locations one at a time:
   • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   • HKEY_CURRENT_USER\ SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
   • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   • HKEY_LOCAL_MACHINE \SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
2. Check the path of the entries. Right-click on the entry and select Delete if they have the incorrect path.

   

   Changes made under HKEY_CURRENT_USER will only be applied to the current user account being used, while changes made under HKEY_LOCAL_MACHINE will be applied to all user accounts in the computer.