Guide to using Memtest86+
Memtest is a small boot loaded program that allows a user to detect faults in his or her RAM . It comprises of a series of tests that puts the RAM under different stresses such as transferring different amounts of data across the channels quickly thereby testing how well it copes, and at the same time checking for accuracy and errors in the data transferred.
Common symptoms of bad ram
There are many indicators of bad memory, some of which can be completely overlooked but generally they come down to the following:
- Computer not booting at all, beeping endlessly.
The computer may display just a black screen with the computer still being on or restarting. Also a POST beep may be heard which indicates hardware faults. There are different sequences of beeps and so research must be carried out to ascertain whether its a RAM fault or not.
However remember different motherboard manufacturers have different POST beeps and so the correct sequence of POST beeps for one motherboard may not mean bad RAM on another.
- Distorted graphics on the screen.
One of the stranger indications of bad memory. Ive seen so many users put this down to graphics cards. The user has then gone and bought themselves a new £100 graphics card to find out their £20 stick of RAM was the fault. This is a great point to which to use Memtest, just to make sure of the fault.
- Blue screens of death during the installation of Windows XP, Windows 2000 and Vista.
This is an obvious sign of faulty RAM. A Blue Screen Of Death is an error screen displayed by some operating systems, most notably Microsoft Windows, after encountering a critical system error which can cause the system to shut down to prevent damage.
As there is no driver that can go wrong here and other hardware wont have fully been configured, faulty RAM will be the reason for the error in most cases.
- Crashes or Blue screens during normal operation of the system (emails, web surfing etc.)
General use of faulty RAM will produce a Blue screen. However again don't automatically assume this is RAM associated. There are hundreds of different items that could cause these symptoms and so diagnostics are required.
- Crashes during memory intensive tasks such as using Photoshop, playing 3d games etc..
When intensive programs are used there is a greater risk of hardware over-stressing itself, thus causing errors. This is actually an area of testing completed by Memtest to check for RAM stability.
The general term for this would be stress testing. This is were hardware is put under extra pressure to perform large task. Faulty RAM would not be able to cope in most instances under this pressure thus singling it out as faulty.
Now that you have diagnosed faulty (or the possibility of faulty) RAM you should carry on to set up Memtest. There are 2 versions to choose from but i will be using the CD version due to the easier and much quicker install.
- First Download Memtest from This Link.
- There are several downloads to choose from. For this CD Version you require the link that says:
Download - Pre-Compiled Bootable ISO (.zip)
- Download the file to your desktop.
- If you are using Windows XP or Vista then you can right click the file and choose Extract All
If you do not have Windows XP or above or are running other Operating systems: - Click This Link to download 7Zip. Windows user require the Top link in the list for the .exe version. 64 Bit users should select the 64 bit version.
Others users eg Mac Users should go to the heading below that says Some unofficial p7zip packages for Linux and other systems and download the relevant version.
- Download that to your desktop. Then double click the 7Zip installer and allow it to install on your system.
- Once 7zip is installed right click the Memtest folder (called something like memtest86+-2.11.iso.zip)
- Then click 7 Zip > Extract Here.
You will now have a .iso file on your desktop called memtest86+-2.11
- Now Click This Link to download ImgBurn.
- Download that to your desktop and launch the installer by double clicking the ImgBurn installer icon. Follow the instructions, keeping the settings as the defaults.
- Now when that is installed double click the program icon to launch
- Then click Write image file to disk
- Then insert your Blank CD
- Next click the Browse for File button
and load the memtest.iso from your desktop.
- Then click the large Write file to disk button
.
- The program will then create your boot disk.
First and foremost verify that your disk has burned correctly.
Go to My Computer or Finder on a Mac and go to your CD/DVD drive. Make sure the Disk is called Boot. If not then the burn has been unsuccessful. However if it is called Boot your CD is ready to go

- Now leave the disk in the drive and shutdown your PC.
- Open the side of your Case and remove all but 1 sticks of RAM. You should only have one stick of RAM installed when running Memtest.
Pull the white clips to the side and the stick of RAM should pop out.
DO NOT put your RAM sticks on the carpet or on anything that can create static. This is a sure fire way to kill the components. Place them on some cardboard or in an antistatic bag to reduce the risk
- Turn your PC back on.
- Memtest should now boot. If not, go to the FAQ below.
- No more user involvement is required at this stage. Memtest will automatically start the tests. The images below show Memtest scans in progress.
- Once Memtest has completed its scan note down any errors that occurred. However usually you will be the one to stop the scan. You can stop the scan at any time but I would advise you run it for at least test number 8 as shown in the image below near the top right hand corner of the screen.
- Then repeat the steps above for the remaining sticks of RAM by opening the case and swapping the existing stick with the one that has not been tested and then re run Memtest.
What it means:
The image below outlines the various areas of the Memtest screen.

Other Tests
This image shows a current scan being performed with Memtest86+

Failures
The image below shows a system with failures within Memtest. As you can see in the left hand Column it shows the failures were all made within test 3. Any failures would normally lead you to have to replace the RAM module as its usually something that isn't repairable.

FAQ
Memtest didn't run when i turned on my computer
This is the most common problem with Memtest and falls down to a problem in your BIOS.
To fix this:
- Turn off your PC wait 10 seconds and then Turn it on again.
- When your PC loads and gets to the POST screen it will say something along the lines of Press DEL (delete) to enter setup. See This Image as an example.
- When you enter the BIOS use your arrow keys to move to either the Main, Advanced or Advanced BIOS Features Tab.
- You will be looking for a list that says Primary Master, Primary Slave etc. See This Image for help.
- Then Navigate down to Primary Master (using the arrow keys) and then using in most PCs the + and - keys change the primary Master to CD-ROM /DVD-Drive or something similar
- Then change Primary Slave to Hard Disk or Hard Drive what ever is available.
Is this test 100% accurate?
These tests are here to try and ascertain errors in your RAM. Some tests could come back as failing due to other reasons such as the program itself. Therefore the results will not be 100% accurate.
I have an error, now what
Most errors found in Memtest will require you to replace your RAM. This is because the problems are found more in the hardware of the RAM and how it works. Therefore it would be difficult for the Average user to repair. Please see the Hardware-Components-Peripherals Forum for more help.
I have more than one stick of RAM, does this matter?
Yes. Being able to diagnose each RAM stick individually is important as only one stick of RAM could be faulty saving you money if a replacement is required. When scanning with Memtest make sure you only have 1 stick of RAM installed at a time to improve the scanning results.
You can also check out This Video contributed by Ferrari if you need more help or if the steps in this guide don't quite work out for you
Thanks also to rshaffer61 for helpful advice and corrections given.
Edited by rev_olie, 24 August 2009 - 05:23 PM.