# PFN List corrupt, IRQL Not Less or Equel



## Bdweller (Jun 8, 2005)

Are these memory errors?

My system started rebooting at random times. Some times I could boot into safe mode and sometimes not. These two errors started appearing: PFN List corrupt, IRQL Not Less or Equel. At one point they appeared when I had formated the hard drive, and there was no OS on the computer.

I had purchased the system used 2.08 AMD, WinXP Home, 512 ram. I added 512 more when I bought it 5 months ago. I pulled the original 512 in bank 0, and now the system works again. 

Does memory fail after time? Is there anything I can do with this memory now?


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## 1_rob_1 (Sep 19, 2005)

9 times out of ten this is a memory error, (sometimes other hardware but probably not in your case). memory can last 20 secs or 20 years, there is no exact lifespan.
In answer to your other question, yes you can do something with this memory now.....................Bin it.

If you had never used this memory, I would have just said that it was not compatible with your system


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## Bdweller (Jun 8, 2005)

Thanks Rob,

This was the memory that came with the system in bank 0, the stuff I bought is in bank 1. And it all worked fine for over 5 months.

I guess I'm just glad I was able to figure out what was going on. Messed up my weekend though I can tell you that for sure.


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## 1_rob_1 (Sep 19, 2005)

No prob


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## edd080 (Dec 15, 2003)

Hi sorry to continue onto this old thread,but iam having a similar problem with my PC, i currently have ;
Asus Am2 E SLI Mobo
Athlon 64 X2 Dual Core 3800+ (Windsor) (Voltage 1.376)
1GB Ram
Sata II 400 GB Samsung HDD.
Nvidia Geforce 6500 256MB

My problem is that whenever i boot up to XP i get a BSOD with a PFN LIST CORRUPT error, i have checked my memory with the windows diagnostic tool and found nothing, i also checked my HDD for errors, still nothing wrong. 
I also overclocked my CPU using the bios menu of my ASUS, through the AI function where i overclocked from 2GHZ to 2.10GHZ. Although i dont remember if the error was coming before i also overclocked my CPU and consequently after. 
If anyone can help me i would appreciate it very much as i have just built my PC and is still under warranty.
Thanks alot for your help.


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## norton850 (Mar 9, 2004)

If you overclocked your system I'm not sure it is still under warranty. Have you tried putting it back to the defaults to see if you still get the error.


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## edd080 (Dec 15, 2003)

I overclocked it through Asus own function but i will try setting it to its default setting and see how it goes,will keep you posted


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## edd080 (Dec 15, 2003)

Ok i have downloaded and upgraded my bios as there was an update for it after the update it automaticaly sets everything to default settings, i have rebooted several times and no error (touch wood)  till now. I hope this will settle my problem,thanks for your help :up:


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## RichGarner (Aug 12, 2008)

I need to piggyback here as well. I'm having similar problems.

I have 2.5Gb off DDR ram (1 stick of 1Gb and 3 sticks of 512) in an AMD Athlon64 3800+ machine with an nForce4 Ultra mobo and Nvidia 8600GT card. System has been working fine for 4-5 months, then suddenly I began to get BSOD at random times... even when I'm not using the system.
I ran memory tests and determined the 1Gb stick to be faulty. I removed it, ran memory test again and everything passed with flying colors.
But I STILL am getting the BSOD. Memory still passes fine. What could be wrong?


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## edd080 (Dec 15, 2003)

Hi, when you re-seated the memory, did you put it into a different slot or into the same slot it was before, apart from that, I had an identical problem as you had, whenever i run a memtest the module would result to be faulty i remove the module, & put it back in the same slot, run a test again, & it would result Ok. However the module would still be faulty & so i had to change it.


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## RichGarner (Aug 12, 2008)

But how can I be sure? I don't want to spend money on new ram if the mobo is faulty. And I don't want to put bad ram in a new mobo. 
This has happened to me time and time again. I THINK I know what the problem is, but when I go slap money down for a new part, it turns out to be something completely different. I just want to be at least 95% positive.


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## edd080 (Dec 15, 2003)

If you try a different slot in your mobo does the ram test out to be ok, also, if everything turns out to be fine are there any particular errors if you check your windows event viewer?


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## RichGarner (Aug 12, 2008)

I'll try those ideas and let you know. I'm currently logged into work from my Linux dual boot on the same machine. 
Funny, Linux works fine. But this same machine burps BOSD every two minutes under XP. Not surprising.


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## edd080 (Dec 15, 2003)

The problem with my ram was whenever i downloaded large files (3GB & over) the download would complete itself without any problems. But when i uncompress the file with winrar or winzip i would get a corruption error, that was very strange  , after the endless testing of my system it turned out to be faulty ram, as it seemed that downloads relied heavily on ram usage or at least that's what i was told, however, after changing the module everything worked out fine.


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## RichGarner (Aug 12, 2008)

I replaced the ram in a different slot and it tested fine. But then the one in the first slot (originally tested fine) had errors. 
Now, no matter what configuration of memory sticks I have in there... XP keeps crashing between 5-15 minutes in.
And I get different errors... PFN list corrupt, IRQL error... sounds like it's a bad mobo. 

Ticks me off. It's an BFG Nvidia nForce4 Ultra and I've replaced it twice for the same exact problem.


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