The Windows Memory Diagnostic tests the Random Access Memory (RAM) on your computer for errors. The diagnostic includes a comprehensive set of memory tests. If you are experiencing problems while running Windows, you can use the diagnostic to determine whether the problems are caused by failing hardware, such as RAM or the memory system of your motherboard. Windows Memory Diagnostic is designed to be easy and fast. On most configurations, you can download the diagnostic, read the documentation, run the test and complete the first test pass in less than 30 minutes.

To run Windows Memory Diagnostic, you must reboot your computer with the disk or CD-ROM on which you installed Windows Memory Diagnostic in the drive. After the reboot, Windows Memory Diagnostic will load and its interface will appear. After loading, the first test pass will begin, using the default standard test suite, and continue until complete, unless Windows Memory Diagnostic is either paused or exited. Once the first test pass is complete, Windows Memory Diagnostic will begin a second test pass using the same settings as before. Windows Memory Diagnostic will continue to run test passes until you exit.

System requirements:

Windows Memory Diagnostic supports x86-based computers with the following microprocessors:

- Intel(tm) - Pentium or Celeron families
- AMD - K6, Athlon, or Duron families
- Microprocessors compatible with those listed

You can test all types of RAM that run on x86-based computers with the supported microprocessors. However, if you have error checking and correcting (ECC) RAM, Windows Memory Diagnostic may not report any errors because the ECC mechanism automatically detects and corrects the error. It might still be useful to run Windows Memory Diagnostic if you have ECC RAM because it may detect errors that the ECC RAM is unable to correct (which indicates problems with the RAM).

Windows Memory Diagnostic is limited to testing only the first 4 gigabytes (GB) of RAM. If you have more than 4 GB of RAM, the remaining RAM after the first 4 GB will not be tested by Windows Memory Diagnostic.

Memory tests:

Windows Memory Diagnostic includes a comprehensive set of memory tests that provide varying degrees of testing thoroughness. The tests are organized into three predefined test suites: basic, standard, and extended. These categories reflect, in increasing order, the time for each test to run as well as the probability of the test detecting errors. The standard test suite includes all of the tests in the basic and standard categories. The extended test suite includes all of the tests in the standard test suite plus the tests from the extended category. The extended test suite takes the longest time to run and is the most thorough test suite.

Each test consists of a testing algorithm, a microprocessor cache setting of either on or off, and a test pattern. Each algorithm is designed to identify a certain type of memory error. The algorithms are combined with different microprocessor cache settings and test patterns to identify different types of errors