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Frequently asked questions

General​

What is O&O RegEditor?​

O&O RegEditor is a free registry editor for Windows. It provides full access to the Windows registry database, with a familiar key tree and value list plus productivity features such as an enhanced search, favourites, address-bar navigation, and a modern interface with dark mode and High-DPI support.

How is it different from the Windows Registry Editor?​

O&O RegEditor keeps the familiar layout but adds an enhanced search with a result list and live results, regular-expression and whole-word matching, the ability to save search results to a file, copying and moving of keys and values, favourites management, an address bar with history, dark mode, High-DPI-crisp icons, and a choice of interface language.

Is it safe to edit the registry?​

Editing the registry is powerful and can affect the stability of Windows. It is safe when done carefully: back up first, export the key you are changing, change one thing at a time, and know what each change does.

Keys and values​

What is the difference between a key and a value?​

A key is a container, like a folder, and can hold values and further subkeys. A value stores actual data (text, a number, or binary content) under a name inside a key. See Registry structure.

Which value type should I use?​

Use the type the software expects. Text is usually REG_SZ, small numbers REG_DWORD, larger numbers REG_QWORD, lists of strings REG_MULTI_SZ, and raw data REG_BINARY. See Value types.

Can I enter a number in decimal instead of hexadecimal?​

Yes. The numeric value editor switches between hexadecimal, decimal, and binary. The stored number is the same regardless of the input format.

Where does a search look?​

A search covers the key you selected in the tree and everything beneath it, across the parts you enable (Keys, Values, Data). Select a specific key to keep the scope small.

Can I use regular expressions?​

Yes. Enable Regular expression (RegEx) in the Find pane. O&O RegEditor uses ECMAScript syntax. See Regular expressions.

Can I save what a search found?​

Yes. In the result list, choose Save Results As... to write the results to a re-importable .reg file or a tab-separated .txt file. See Search results.

Files​

Are the exported files compatible with Windows?​

Yes. Exported .reg files use the standard Windows registry-file format and can be imported by the Windows Registry Editor and by O&O RegEditor.

How do I undo a change?​

If you exported the key before editing, import that file to restore the previous data. See Import.

Settings​

Where are the settings stored?​

In a portable configuration file (OORegEditor.cfg), either next to the program or under %LocalAppData%. Settings from earlier versions are migrated automatically. See Settings reference.

Can I run O&O RegEditor portably?​

Yes. Place an OORegEditor.cfg file next to the executable and it is used in preference to the per-user configuration.

Troubleshooting​

A change was refused. What should I check?​

You may lack permission on that key. Start the program with administrator rights and check the key's permissions. See Troubleshooting.

Dark mode is not available. Why?​

Full dark-mode support requires Windows 10 version 1809 or later. On older systems the light theme is used.