is intended to be a one-stop shopping place for memory
diagnostics. Comments and suggestions are welcome!
SKIP TO STEP 7 if that was recommended on the forums (to isolate problems)
- a blank CD (USB key if using the bootable USB drive test)
a computer with an internet connection where you can download a file,
install a small program, and burn a CD (doesn't have to be the computer
that you'll be testing).
Windows Vista and Windows 7 have built in diagnostics. Use
them if possible, instructions are here: http://www.bleepingcomputer.com/tutorials/using-vista-windows-memory-diagnostics-tool/ NO
have been issues mentioned (on the web) with the use of the in-built
Windows memory diagnostics. Because of this (and because they
usually only run one pass) I no longer recommend using them. The
links are left in case you would like to try using them.
Bootable memory diagnostic tests:
Description here: http://www.memtest.org/
Downloads here: http://www.memtest.org/#downiso
Download the file from here (direct download): http://www.memtest.org/download/4.20/memtest86+-4.20.iso.zip You
must unzip the file before
you can burn (NOT copy)
the ISO image to a CD. Here's a direct download link for the USB flash drive version: http://www.memtest.org/download/4.20/memtest86+-4.20.usb.installer.zip
Other tests that I've found:
http://www.memtest86.com/ (v3.5 has issues w/4+ gB of memory - use v3.4a instead)
http://hcidesign.com/memtest/ (haven't tried this one myself)
USB BOOTABLE TEST: http://www.pendrivelinux.com/testing-your-system-for-usb-boot-compatibility/
Memory Diagnostic NO
Description here: http://oca.microsoft.com/en/windiag.asp
Download the file from here: http://oca.microsoft.com/en/mtinst.exe
Extracting the .exe file will allow you to save an ISO file onto your
If you do not have a disk burning program that's capable of burning ISO
images to your CD drive, I suggest this free tool: http://isorecorder.alexfeinman.com/isorecorder.htm
Select the appropriate version by following the instructions, Install
the program, then reboot your system.
an ISO burner will place files in a certain order on the disk, this is
what makes the disk bootable. You CANNOT
just copy the file to a CD - it won't work!
Insert the blank CD into the CD drive and dismiss any dialogs that may
pop up. Then right click on the ISO file that you downloaded
select "Copy Image to CD" (it should be the top choice on the context
(right click) menu. Follow the prompts to record the
Remember that the slower the speed you select, the less likely it is
that there will be errors in the burn process. Most disk
are small, so the process shouldn't take very long even at the slowest
5. Boot from the CD to run the test. Here's a partial list of
to access the built in boot menus of different systems. Press
appropriate key when the first screen shows up after you turn the
HP/Compaq - Esc (starting to use F9 also) (F10 will usually access BIOS)
Dell - F12 (F2 will access BIOS)
Gateway/eMachines - F10 (moving to F12 with newer models) (F2 will access BIOS)
Acer - F12 (not always) (F2 will access BIOS)
Toshiba - F12 (older systems will be different)
Sony - usually will boot to CD, may ask you to "Press any key to boot
Asus - Esc (F2 will access BIOS) F8 on some systems (mostly older). Tab will display the boot screen
Samsung - Esc (F2 will access BIOS)
Nokia - F12 (F2 will access BIOS)
Lenovo - F12 (?Del wil access BIOS)
in doubt, either access the BIOS (Setup) and make the CD drive the
first boot device (before the hard drive), or post in the forums for
Follow the prompts on the screen to run the test (some versions will run automatically). Run the test
minimum of 3 passes (some recommend a minimum of 7).
better. There's some discussion that I've seen that running
test too long will generate errors eventually even if the RAM is good -
I doubt that this would be true with an overnight test.Additionally,
if you still suspect memory errors, try testing one stick at a
time. The user in this thread found errors in one of their sticks
that had already passed the testing of all sticks: http://www.sevenforums.com/crashes-debugging/178451-random-bsod-3.html#post1642914
the test starts spitting errors, stop the test. If
unsure it's the red stuff in the bottom half(s) of these
The next step
involves opening up your computer.
NOTE: You can remove the CD/USB key once the test has started.
6a. Run 2 tests
- a test on the system the first thing in the morning (when the system
is cold) and then another after the system has run for an hour or two.
If it doesn't run in Windows, run the memory test for ½ hour,
then shut down and start it over. This is because we've been
seeing some issues with test results that differ when the system is
cold and when it's warm.
6b. Reseat the memory (and clean the slots out with canned air) and retest
- If your system spits out errors, then reseat the RAM and run
the test again. It should quickly tell you if the RAM is still
bad, or if it was just a problem with dirt/dust in the slots.
This was my first great embarrassment when working in a PC shop -
luckily I sent the guy to another shop for a second
opinion!!! Only used canned air - don't use a vacuum or an
air compressor as they can cause damage (and blowing with your mouth
can leave spit in the slots).
6c. Run Prime95
- This test
will stress the memory and may throw errors when MemTest86+ doesn't.
Use this when there are suspected memory errors but the
previous tests have passed. An example of this is found in this
To open your computer, first unplug the system by pulling the plug from
the back of the computer. If it's a laptop, also remove the
battery. Open the case so that you can access the memory
and blow any dust out of the case (so it doesn't get in the slots and
cause problems with the connection). Also, hold
the power button down for 30 seconds (after unplugging) to ensure that
the circuit closes and all components drain any accumulated
charge. Then ground yourself by
holding onto the metal of the case (to prevent static discharge from
damaging the memory chips). Remove the memory sticks by
unlatching the clips at either end (Desktop) or on the sides of the
modules (Laptop). Note that the sticks have little notches in
them to ensure that you put them back in the correct way.
Insert one chip in the first slot (it doesn't matter which one you
choose, as long as you keep track of them). You will feel the
clips snap back into place when doing this - but double check to make
sure that they're solidly inserted. Then plug the system back
and run the memory test. Make sure that you keep track of
chips you have and which slots you've tested them in.
Once the test is done unplug the computer again, hold the power button down for 30 seconds, and ground yourself on
the metal of the case. Remove the chip and set it
Then test the rest of the chips one at a time - following the steps
that is done you'll know which chips passed the test and which
didn't. There's 3 possible outcomes here:
- all the chips passed the test
- some of the chips passed the test
- none of the chips passed the test
any of the chips passed the test, use that one to test the rest of the
slots. If all the slots test good, then it's safe to assume
the chips that tested bad are bad. If the chip only passes in
some of the slots, then it's likely that the slots that it failed in
are bad (which means a problem with your motherboard).
none of the chips passed, then it's either that all the chips are bad,
that the motherboard is bad, or that both are bad. To figure
which it is, you'll have to either test the chips on another, known
good motherboard, or you'll have to purchase new chips and test them.
As always, if there's any problems with this or if you get results that
you don't think agree with the testing, please post in the forums for
help with resolving it.