[EricJB]

Hey all,

I seem to be having a problem with my PC crashing which just started today out of the blue. The PC just rebooted on me suddenly and when it got back to the screen asking me if I wanted to boot into safe mode, I selected Start Windows Normally. It then blue screened on me.

I'm running Windows 7 RC dual boot along with Windows XP. I thought it was a problem with Windows 7 but when I tried XP, that crashed as well. It usually crashed as soon as I click on one of the login accounts on the Windows Login screen, and this happens for both the XP and Win 7 partitions.

I left the machine off for a few hours and when I turned it back on, everything was running fine for about 15 minutes before it rebooted on me. This time, I selected Windows Memory Diagnostics Tool. It said that a hardware problem had been detected but the PC crashed again before it was done running the test fully. After the reboot, I selected safe mode, which also crashed upon login. Finally, after another reboot, I selected the option to stop allowing the PC to reboot automatically after a crash. This time, I got a blue screen with a STOP (Fatal Error) message. The code was C000021a.

Does this sound like anything familiar at all to anyone? The PC has been running fine. I haven't added anything new, hardware or software, for a little over a week. I literally just turned the PC on this morning, like I do every morning, and the problems started occurring.

Thanks in advance, hopefully someone has some ideas.

Forgot to add: I don't think it's a heat issue because I have pretty good airflow and I just recently (about a month ago or so) replaced the CPU's heatsink with a brand new Thermaltake model. I've also been checking speedfan when I can and it's not reporting any temps that are out of the ordinary.

Edited by EricJB, 22 August 2009 - 07:18 PM.

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Defective memory, on the basis that Memory Diagnostics has fell over.
Google a copy of MemTest86 and leave it running for a few hours.

[Neil Jones]

Defective memory, on the basis that Memory Diagnostics has fell over.
Google a copy of MemTest86 and leave it running for a few hours.

[rshaffer61]

Her you go Neil. Maybe this will help you.
Let's check your memory and make sure there is no issue with it. Download memtest86 from the link in my signature below.


Get the file that is named Download - The one you want is "Download - Pre-compiled Bootable ISO (.zip). When it downloads, it will be labeled memtest86+2.11.iso.zip
Unzip the file once you download it. You should have a .iso file in the unzipped directory. It will look like a zip file in some cases but the file name will now be memtest86+2.11.iso

if you don't have a burning program that will burn .ISO files get burncdcc in my signature below.

NOTE...do not put a blank cd in until burncdcc opens the tray for you
1. Start BurnCDCC
2. Browse to the ISO file you want to burn on cd/dvd ....in this case its memtest86.iso
3. Select the ISO file
4. click on Start

Make sure the bios is set for the cd drive as the first boot device
Put the cd in the cd drive and then boot your computer.

Running the Diagnostic Program:

The basic diagnostic screen has five main sections of relevant information. Three at the top which are labeled, PASS %, TEST %, and TEST #. This will basically show you the total progress of the current test, the overall progress of the diagnostic test, and the test number is currently performing.

On the middle left hand side of the of the program interface there is a “Wall Time” section that will keep track of how long the diagnostic test has been running for. This just gives you an idea if you are not attending the testing process.

The main section to look for is the lower half of the screen which is usually blank. As long as the memory testing is going ok with no errors this section of the screen should remain blank. If the diagnostic program finds any serious faults in the memory you will see it display a memory dump of address’s in this section. This is similar to what is displayed on your screen when you encounter a blue screen of death.

You now have most everything you need to know about setting up and testing your memory with diagnostic programs. This guide should help you get to the source of any intermittent problems related to your memory.

Run memtest for at least 2 hours
If it starts showing any errors during that time then you will have to replace the memory
If there are no errors after 2 hours press Esc and that will end the tests
We will then try other options

[EricJB]

Hey guys... Thanks for the replies.

OK, ran Memtest86+ and it showed up 26 errors. I have three sticks of RAM in the machine at the moment. Two sticks of 512MB that came with the PC way back in 2005 and one stick of 1GB that I bought just when Circuit City was going out of business, so not too terribly long ago.

Thanks again!

[rshaffer61]

Rerun the test on one stick at a time.
That hopefully will narrow it down to a single stick for you.

[EricJB]

OK, just ran a full test on each stick individually and all three came through with no errors. Strange, considering when I ran the test with all three together the first time, it found those 26 errors.

Is this odd?

Thanks.

[Neil Jones]

OK, just ran a full test on each stick individually and all three came through with no errors. Strange, considering when I ran the test with all three together the first time, it found those 26 errors.

Is this odd?

Stranger things have happened.
You need to run the checks with each stick of memory in each slot. It's entirely possible one or more of the memory slots is faulty and you've done your testing all in the same slot which just happens to be good.

[EricJB]

OK, just ran a full test on each stick individually and all three came through with no errors. Strange, considering when I ran the test with all three together the first time, it found those 26 errors.

Is this odd?

Stranger things have happened.
You need to run the checks with each stick of memory in each slot. It's entirely possible one or more of the memory slots is faulty and you've done your testing all in the same slot which just happens to be good.

Actually, what I did was put each stick back in the same slot it came out of when I did the individual tests. Right now I've only got the 1GB stick in and I haven't crashed or anything since running these individual tests.

Think I should stick the other two back in and run the test again? Could it just have been a dust build up or possibly one of the RAM chips coming loose? I did just change PC cases about two months ago or so. When I moved the mobo I left the RAM untouched.

Anyway, in my system, I've got a 512MB stick in the first slot, the 1GB stick in the second slot and the other 512MB stick in the third slot. Then the 4th slot is empty. I did it this way because the two 512MB sticks came with the computer when I bought it and they were already installed in those slots so I just left them untouched and when I added the new 1GB stick, I just stuck it in the 2nd slot since it was the first one not in use.

Thanks, I appreciate the insight.

[Neil Jones]

Could have been static build-up between modules and board, or the concept of "memory creep". Memory creep is caused by the modules gradually working their way out of the slot over a period of time as the machine is powered up and down. Serious cases result in the computer not booting at all.

[EricJB]

Could have been static build-up between modules and board, or the concept of "memory creep". Memory creep is caused by the modules gradually working their way out of the slot over a period of time as the machine is powered up and down. Serious cases result in the computer not booting at all.

Yeah, because I put the other two RAM sticks back in and it's been running fine all day now. Guess it was something along those lines. Hopefully it stays running and we solved the problem.

Neil and rshaffer61, thanks a lot guys!

[rshaffer61]

You are very welcome. I'm glad we could help and please let us know how everything works out for you.
If there is anything else we can do to help please feel free to ask. I appreciate that you allowed me to assist you with your issue and for your patience. Thank you for choosing GeeksToGo for help.