What to Know

  • An HDMP file is a Windows Heap Dump file.
  • Open one with Microsoft Visual Studio.

This article explains more about HDMP files, including why they're created, how to find them, if deleting them is okay, and how to open one if you need to.

What Is an HDMP File?

A file with the HDMP file extension is a Windows Heap Dump file used for storing uncompressed error files generated, or “dumped,” when a program crashes in some versions of Windows.

Compressed dump files are stored in the MDMP (Windows Minidump) format and are used by Windows to send the crash reports to Microsoft.

Screenshot of several HDMP files in Windows 10

How to Open an HDMP File

Error dump files can be opened using Microsoft Visual Studio through its File > Open menu. Recent versions of the program can open HDMP, MDMP, and DMP (Windows Memory Dump) files this way.

If you're using a version of Visual Studio that doesn't seem to let you open the file, just rename it to use the DMP file extension and try again. If you get an error about "not enough storage," it's likely that the dump file is too large for Visual Studio to load into memory.

You can safely remove HDMP and MDMP files from your computer if you don't want to investigate the cause for the errors or if they're taking up too much disk space. However, if the problem persists, it's likely that more of these dump files will be created. As with all computer problems, it's always best to resolve them before they get out of hand.

How to Convert an HDMP File

We're not aware of any way to convert an HDMP or MDMP file to any other format.

More Information on Dump Files

The Windows Registry location that holds error reporting information is in the HKEY_LOCAL_MACHINE hive, within the Windows Error Reporting key:

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsWindows Error Reporting

The folder that programs typically hold dump files in may be called dumps or reports, and is typically found in the program's installation directory. However, others might keep these files in a totally different folder, like DellDataVault for Dell programs, for example, or CrashDumps.

If you need help finding an .HDMP, .MDMP, or .DMP file on your computer, one easy way to search for it is with the free tool Everything.

To create a DMP file while a process is running, you can do so through Task Manager. Just right-click the process you want the dump created for, and then choose Create dump file.

Still Can't Open It?

Windows dump files might use the HDMP, MDMP, or DMP file extension, and some file formats use a file extension that closely resembles those, making it really easy to confuse one format for another.

For example, HDML is spelled almost the exact same way but is used for Handheld Device Markup Language files. If your file isn't opening as described above, check that it really does end with ".HDMP," because HDML files open with a different program.

It's just as easy to confuse MDMP and MDM files. The latter might be in the HLM Multivariate Data Matrix file format or the Mario Dash Map file format, but again, neither are related to HDMP files.

DMPR files are easy to mix up with DMP mail projects used by Direct Mail. Yet another example is the DM file extension.

HDMI is a common search term that has a similar spelling as HDMP, but it has nothing to do with this format or any file format. HDMI stands for High-Definition Multimedia Interface.

If you don't have a dump file, be sure to research the real file extension for your file to learn which programs can open or convert it.


  • How do I use WinDgb to analyze a crash dump?

    Search for WinDbg > right-click the result and choose Run as administrator. Then select File > Start debugging > Open dump file > enter the MDMP folder location. Next, select Open, go to the command bar and enter !analyze -v. If you don't have the WinDbg tool, learn about downloading Windows Debugging Tools.

  • How do I open MDMP files?

    Use Visual Studio to open MDMP files. Select File > Open > File > find the MDMP folder (which is usually located in C:WindowsMinidump) > OK. To debug the file, go to Actions and choose from four debugging options.