These files are created when your operating system or application crash. Programmers use these files to find what cause your OS or program to fail.
The problem with these files is that they will sit around for a long time sucking up space. The file size can vary from a few kilobyte to a few gigabytes.
If you run the following command from the Command Prompt it will find these files and show you where and how big they are.
for /r c:\ %i in (*.dmp) do @echo %i ^(%~zi^)Note: This command needs to be entered exactly as shown. You can change the .DMP extension to something else if you want to (i.e.: .TMP). You can also change the drive letter (i.e.: C:\) as appropriate.