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I'm fixing a desktop for a friend, after their Windows installation died. Reinstalling windows led to numerous BSODs during installation (IRQL_NOT_LESS_OR_EQUAL being the most common). After finally installing XP again, it worked for a while so I installed SP3. And it died again.

So I decided to test the RAM. My Linux LiveCD had memtest86+ 2.11 on it, so I ran that. It's now at 51% with just under 2 million errors. My laptop passes the test without any problems, so it's not a problem with the memtest on the disc. This presumably means the RAM is very bad, but it was able to run the Linux LiveCD for about an hour to back up the system without any problems.

Is the problem definitely the RAM, or is something deeper wrong? I don't want to advise this friend to buy some more RAM, and then find out that the motherboard is fried.

EDIT: In case it makes any difference, the PC is a Lenovo ThinkCentre A58. It's got a 320GB HDD, and original came with Vista and XP discs, but the Vista disc has been lost.

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up vote 3 down vote accepted

First step - unseat and reseat the memory, sometimes it is just loose which can cause problems.


If you have two memory sockets and one stick of memory - put it in the other socket and test

If you have two memory sockets and two sticks of memory - rotate both of them.

If you have one socket and one stick of memory - You can try a spare.

In Memtest86+, one error or one million errors doesn't really make a difference, if it is bad, its bad.

As for running Linux for some time, you can just get lucky and not "hit" the bad part of memory... or a file could be corrupt and you may not know (but this is rare) - there is simply no easy way to find out.

Typically with Memtest86+, I find that 99% of the time, the problem is related directly to bad memory, but 1%, it is possible that there is another fault such as a blown capacitor which leads to random memory errors.

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It is not necessary that your modules are bad -- you could have other problems.

Check out the Troubleshooting Memory Errors notes at the Memtest86 page.

Please be aware that not all errors reported by Memtest86 are due to bad memory. The test implicitly tests the CPU, L1 and L2 caches as well as the motherboard. It is impossible for the test to determine what causes the failure to occur. However, most failures will be due to a problem with memory module. When it is not, the only option is to replace parts until the failure is corrected.

Once a memory error has been detected, determining the failing SIMM/DIMM module is not a clear cut procedure. With the large number of motherboard vendors and possible combinations of memory slots it would be difficult if not impossible to assemble complete information about how a particular error would map to a failing memory module. However, there are steps that may be taken to determine the failing module.

Here are four techniques that you may wish to use:

  1. Removing modules
  2. Rotating modules
  3. Replacing modules
  4. Avoiding allocation

more notes at that link.
And the Memtest86 current pages.

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to rule out other hardware faults with certainty, you will have to run Memtest86+ on this computer again with different memory modules that you have been testing error free on another computer.

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