i still ended up having the same problem later, i ran across this fix in a travel site forum.
you have to edit the registry but i have had no problems since, seems my pc doesn't like some software and then you can tell if it is hardware or software giving error.
the solution:

Start -> Run -> Regedit

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session
Manager\Memory Management\PrefetchParameters

EnablePrefetcher -> 1

Set EnablePrefetcher to 1

mine was set on 3, changed to 1, poof it boots with 3 lines or less on xp startup instead of hd flashing for 10-15 seconds ang getting 10+ device\harddisk0\d during a paging operation.

no guarantees but it had no ill effects on xp starting or running just got rid of the error.

Hope this helps, can't hurt...

GOOD LUCK AND HAPPY CAMPING

opps double post... sowwy

I have this problem for almost two weeks, now. My system worked fine since my pc is bought, and that is two and half years, to be precise. A half year ago, I bought new HDD cuz old one was noisier than usual, and since than, from time to time, there was some slight problems with discs, but nothing too problematic. In last two weeks series of problems started to happen. Error 51 was actual and always followed with error 5,9 and 11. That resulted with temporal freezing. Later it resulted with total freezing. I couldn't restart my computer normally, only after i unplugged an plugged back sata cables. That solved problem for some time, but that itself was not solution. My first though was that I have problem with system. I made repair about month ago. When my problems started, I noticed it occurs only when I do something aka copying files, watching movies, after returning from standby to working mode, etc. My though was pointed to new hdd, but it worked fine since it's bought, and made no problems so far. And i tried to both of my hdds individually. I have different OS on each of them, so that would indicate system error. Unfortunately, both systems reporter the same error, and xp even went to blue screen. So, the problem was not with hdd, or both hdds are screwed .
And than I recalled something that happened but should not happen. I played some old game when power in my house gone off. Because that happens sometime, I secured my pc wit good APC UPS which I have almost as long as I have this pc. Usually, when I experience power loss, no matter what I do, I still have enough power to play game for five minutes, or to keep pc turned on for half an hour. But this time, my pc did restart instead.
That gave me final though. Problem could be with sata ports on motherboad, or motherboard itself. But, I was almost 100% sure that was problem with power supply unit. And then I removed all unnecessary parts of computer: second hdd, cd drive, modem, and I also switched sata cables. Pc works without problems so far, but I will change PSU as soon as I can.
My final though is that problem of this error is PSU. From what I could read, most that complained had two hdds, and I suspect that crashing of the hdd was caused because voltage was simply not enough. So, before you make yourself into unnecessary registry edit and system setting, try to ease your PSU for only most important parts.

It seems most of the time is due the PSU or railings. Recently my new hard drive started with the drat message and i moved around a little bit the power railings and fixed it, but then, it just a matter of testing.

There seem to be many reasons for this error, from wrong config, to hardware related issues such as weak PSUs and failing HDD.

I eventually solved mine by turning off DMA mode transfers to the slave DVD ROM drive and installing the SiS system and AGP drivers for the main board.

Been stable for over a week now, 24/7 usage. Before this would fail with error 51 every few hours machine checks and lockups.

Hi experts and strugglers

This is a very respectable forum and especially this 5- year, 33 page thread. I read many pages of it in the last couple of days, so I feel obliged to contribute my experience about event 51, another accompanying event {"disk did not respond within the allocated time period"} (don't remember the event number), and computer freeze-ups.

We have a home network of 5 PC, all running Windows XP Pro SP2. (Don't feel any need to switch to Vista or Windows 7). Over the last month, one of the PCs started showing event 51 in the Event Viewer log (pretty sporadically), plus another event {"disk did not respond within the allocated time period"} (I don't remember the event number), and, more problematically, started freezing up (hanging) every 2-4 hours. No clue to the freeze-ups in the Event Viewer. When a free-up occurs, I would hear a disk winding down, the mouse arrow cursor would stagger for a couple of seconds, then the entire PC freezes up (although the screen keeps the last image- no BSOD).

That PC has a pretty old Pentium 4 motherboard (ASUS Award), with on-board IDE controllers, 3 hard discs (one of them 7 years old, the other two - 2 years old each, plus a Maxtor CD burner. 1 GB of RAM on a RAM card plugged in into a mobo socket. HP 7620 color printer on USB.

I've done lots of things to try to diagnose and locate/pinpoint the problem.
I ran checkdisk on all HDs
Ran HD analysis with two HD utility softwares
Disconnected USB printer
Disabled CD burner driver
]Nothing helped. All test were passed - top scores.

Then I tried one last thing which fixed it - I transferred the swap file from "Disk 1" (which by the way was not not the system disk (that is Disk 0)) to "Disk 2", which sits on the second IDE controller. Note that the former disk ("Disk 1") has 2 years of work, and the new disk (:"Disk 2") has 7 years of work.

That fixed the problem.

I'll be glad to hear insights, suggestions and comments about why it had happened, and why was this the solution to the problem.

Gail Hardmann said:

When you refer to "swap file", are you referring to the file used in the virtual memory setting (file name pagefile.sys)?

If so, this certainly won't help me as this error (referring to the "paging operation" in particular) has me confused as my error refers to drive 5, which is an external drive (2 TB Western Digital "My Book") and is not used for virtual memory nor has it ever been used for virtual memory.

I realize you posted your reply a while ago, hopefully you get this.

Cheers,
Scott