I'm not having this particular problem but I believe I've discovered one of the major causes of the error and the simple fix.

Myself and others that I have spoken to regarding this error have come up with some common denominators that lead up to this error message coming up on the screen and the computer not booting, As well, the 'fix' is almost always the same.

Commonly, the computers in question are oned that are left on 24/7 for long periods of time with the only shutdowns in between being brief restarts.

The problem arises when these computers are shut down for an extended period, long enough for the computer and especially the hard drives to cool to ambient temperature, this takes several hours, as the disks are quite hot when at operating temperature.

The cause of the problem is the aluminum platters of the hard disks expand substantially when they are hot and they become 'accustomed' to reading and writing in certain areas of the disk. When the disks are cold the aluminum shrinks and the read/write heads are told by the disk circuitry to look for the data in the last place the data was found only to see that the data is not there.

What is the fix to the problem?

When the computer comes up with the "Boot Disk Not Found" error, Leave it in that state and go for a coffee, come back in 10 minutes and press "Ctrl+Alt+Del" to restart. If it still doesn't restart or gives some other 'file not found error' the disks are not warm enough so repeat the process.

Works for me every time... I'm trying to save some electricity and started shutting down my computer when I go to work and I now have to deal with this everyday. My computer is directly below a window and it I have it cracked open for some fresh air, the computer gets really cold and takes about a half hour to get it to start.

So, when you have this problem, don't call a repair man, don't panic, leave it turned on, go for a coffee, come back and restart it.

Just thought I'd share my experience as it seems to be a common thing that even baffled our 'computer guy' at work.

Watch for this to happen at the office if the computers get shut down over the holidays.

 

That is really good info. Now, my question is this. When in the hell am I gonna get to use the BFH I bought many moons ago????

 

When my 8-track dies, I'll send it to you and you can use your BFH on it.
Then I'll upgrade to one of these...

 

That's odd, I don't think that should be happening. I believe that during the "deep" format process for a hard drive, sync tracks are laid down which allow the heads to adjust to the data tracks. If I had a drive that exhibited this problem/solution I would have considered replacing it.

I'd be interested where you got your info furball? As I don't claim to be an expert in this, it could well be that your info throughly trumps my meager knowledge.

I'll check with our disc drive expert when I see him next, he's pretty good at this stuff...



BTW, the classic situation where you see this error is when you have a non-bootable disc in your floppy drive. If you're young enough to not know what a floppy drive is (my last several pcs haven't had one, and I can't even remember when the last Mac had them) then ignore this...

 

Personal experience, as I explained in the original post. All the reports of computers not starting after being shut down, when the computers are normally left on 24/7 and the same 'we farted around with it for 10 minutes and it started up."

The heat related expansion and contraction of aluminum has been known about for at least a century, I'm sure, and it's negative impact on Hard disk platters for decades, although, the problem is becoming worse as aureal density becomes greater and motors spin faster creating more heat.

 

Yes, there's no denying that aluminum (and *almost* everything else) expands when it gets hotter. But since that is a phenomena everyone is aware of (including disc drive manufacturers) I'm pretty the drives have systems in place to compensate for that.

Plus one other thing - the error message in question means that the a valid boot block on the disk can't be found, and the boot block(s) of the disc are not repeatedly written to - it's written once when the OS is installed and from then on only read from.

But hey, if it works for you I can't argue with success...

 

Interesting theory. I had a similar message on a work computer a last Monday. After rebooting 4 times and getting the same message we left it on to show the computer guy we called to come fix it. After a couple of hours, we got tired of waiting on him and rebooted the computer and it came up with no problems.

Kind of fits with what your saying. Thanks for the tip. It's definitely something to try before you start throwing money at it.

 

ERROR: Boot Disk Not Found / System Disk Not Found.thats kinka like a SES light you know something is not right! i would back up anything you need off that hard drive,because its going to get worse!

 

A boot sector error during a BIOS load should not happen on any computer when referring to how long the system has been up or down.

As you said, a reboot my fix the problem, but it is not the solution. A full BIOS memory dump should be done to see what drivers are failing during the load. I wouldn't disregard this error... it is one of the more critical ones.

 

So how do you do this dump, and then how to you interpret the information afterwards?

 

It's not likely something that the BIOS "dump" will be able to help you with.

Here's the basic issue. When you create a bootable disc (whether it be a HD, CD, floppy, flash/whatever), special boot code is loaded in a location on the disc known to the BIOS. That boot code is what starts the full boot process - it contains code that (eventually) loads the full OS (including the full set of drivers). Since the BIOS knows exactly where to find this code. i.e. there's no file system functionality required. If the BIOS can't find valid boot code on the drive that's been designated as the boot drive, then it fails to boot. It can do a couple of things - throw an error, or try another drive, if there is one. In the case where the BIOS can't find boot code on the any (or the only) disc you have in the system, you'll get the above error. It's the BIOS saying "Hey, I'm running, but I can't find the code I'm supposed to run" This code is generally written once and only once - if it gets corrupted you can sometimes repair the disc by restoring the boot code. But I'd be a bit nervous about why it failed in the first place.

Regardless of your thoughts on this and whether you're seeing problems at time or at all, one thing is indisputable - keep backups of your important information! Like your tax returns, your important emails and all those pictures of the kids! We just had a guy who works maintenance in the build come to us desperate - the HD is his home PC had crashed. We tried every trick we knew of, but couldn't get it up long enough to copy data off the drive. About five years of pictures and videos of his kids - gone. He had no back ups...

 

weird, computers are made to run and not turn off if ya cant because of business's etc.....also a computer shouldnt have a problem of being to cold, unless you leave it outside in january in alaska. they run better cold than they do hot thats for sure.

id imagine your pc will have some issues pretty soon. unless im missing something, but you shouldnt be going through what your going through is all im saying

 

FYI: A follow-up, as promised...

I finally talked to our drive expert - among other things, we do video arrays and servers here, which includes some custom modifications to off the shelf drives. According to him, thermal expansion of the platters (and heads too) is well known and there are mechanisms in the drives to compensate for that. There are "servo bursts" embedded in each track which allow the drive electronics to determine if the head is off center of the track as the platters spin, and the mechanism that moves the heads can make fine adjustments to keep the head centered. There are several different methods of doing this, one of which actually has the servo bursts on either side of the track, one with positive pulses, one with negative pulses. The head can tell if the combined signal from both is more positive or more negative, and will adjust accordingly. Sort of like "keeping it between the white lines".

Also, FWIW, I described the error scenario as noted in the OP, and his opinion was back up your data and replace the drive...