Understanding Registry Value Data Types

by Barry Dysert
(last updated March 31, 2014)

If you ever have to get into the registry, you may be curious to know what value data types exist. Every key's value is assigned a data type. The list of valid data types includes:

REG_SZ. A null-terminated string

REG_BINARY. Binary data

REG_DWORD. A 32-bit number

REG_QWORD. A 64-bit number

REG_MULTI_SZ. A sequence of null-terminated strings, terminated by a null value

REG_EXPAND_SZ. A null-terminated string that contains unexpanded references to environment variables (like %PATH%)

Of course, if you're editing the registry you'll need to use the data type appropriate for the key you're creating. For example, there's a registry tweak you can do that will disable Windows from constantly checking for low disk space (and therefore increase by a bit the amount of resources available for other things). This is at HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies. If you click on the "Explorer" folder you can create a key named "NoLowDiskSpaceChecks". To disable Windows from doing the disk space checking, you want to put a 1 in for that key's value.

Obviously, you could use a data type of REG_BINARY, REG_DWORD, or REG_QWORD since they will all hold the value 1 with no problem. I used REG_DWORD, though, since there may come a time when the key may take on more than two values, so I wouldn't want to be limited to REG_BINARY. And REG_QWORD seems like a lot of space to simply hold a 1.

 This tip (13035) applies to Windows 7 and 8.

Author Bio

Barry Dysert

Barry has been a computer professional for over 30 years, working in different positions such as technical team leader, project manager, and software developer.  He is currently a senior software engineer with an emphasis on developing custom applications under Microsoft Windows. ...

MORE FROM BARRY

How to Run a Program when Windows Starts

It's easy to have a program run when Windows starts. In fact, by using the Task Scheduler, you can have all sorts of things ...

Discover More

Changing User Permissions for a File

All objects on your computer (e.g., files) have permissions that allow or deny various types of access. This tip shows you ...

Discover More

Scanning Pictures with a Scanner

If all you have is a hardcopy picture, you can still digitize it by using a scanner. This tip gives a high-level description ...

Discover More
More WindowsTips

Editing the Windows Registry

The Registry is the central depository of configuration information used by Windows and by programs running on your system. ...

Discover More

Importing a Portion of the Registry

Windows wouldn't function if it weren't for the Registry, and many system tweaks involve editing it. If you've exported a ...

Discover More

Finding Information in the Registry

The Registry is the central depository of configuration information used by Windows and by programs running on your system. ...

Discover More
Subscribe

FREE SERVICE: Get tips like this every week in WindowsTips, a free productivity newsletter. Enter your address and click "Subscribe."

View most recent newsletter.

Comments

If you would like to add an image to your comment (not an avatar, but an image to help in making the point of your comment), include the characters [{fig}] in your comment text. You’ll be prompted to upload your image when you submit the comment. Images larger than 600px wide or 1000px tall will be reduced. Up to three images may be included in a comment. All images are subject to review. Commenting privileges may be curtailed if inappropriate images are posted.

What is seven more than 5?

There are currently no comments for this tip. (Be the first to leave your comment—just use the simple form above!)


Newest Tips
Subscribe

FREE SERVICE: Get tips like this every week in WindowsTips, a free productivity newsletter. Enter your address and click "Subscribe."

(Your e-mail address is not shared with anyone, ever.)

View the most recent newsletter.