Can not find Operating System

Is the computer seeing the hard drive?  If your system doesn't show the drive(s) during the boot up process, you should be able to go into the BIOS and see if it detects it in there.  If it doesn't see it, then there is a possibility that the drive has died on you. (This is the first place to start)

Which fan are you referring to (CPU, case, power supply)? There isnt a floppy disk in the drive is there?

For Win98, I'm skeptical that FDISK/mbr will help, since the message suggests that the partition is being seen, but not the OS.  In any case, however, if the OS is on a FAT partition, booting with a floppy and "looking around" is the first thing to do.  If it's 98, while I'm skpetical that FDisk/mbr will fix the problem, "SYS C:" might, although it might leave you bootable to a DOS prompt rather than to Windows.  If you run a Sys C:, backup the MSDOS.SYS file BEFORE you run it, and be sure that the floppy is for the same OS version as the running system.  Again, this is only for a FAT partiton on drive C:, and primarily for Windows 98.

For XP, do as Callandor suggested, boot from the XP installation CD if you have one (however, being an HP system, you may not have one).  I'd spend a few minutes "looking around" before doing anything, then run chkdsk, even if you don't actually "do" anything (e.g. don't make any "repairs", don't use the "/F" switch, but try to assess what has happened).  FIXMBR and FIXBOOT are worth doing, they may or may not fix the problem but shouldn't do any damage.

Most HP's don't come with a Windows CD, however, and instead have a diagnostic and restore partition on the hard drive.  This won't do you any good if the hard drive is screwed, and I'm not sure, on your machine, how you access that hidden partition -- you may have to call HP.

As to the fan, as dev said, "which fan"??  You might have "fried" something -- power supply, CPU or even the disk drive.

It is the CPU fan.     After work, I will check suggested.

I have a Windows 98 OS

Is this an Intel or AMD CPU?  There's a good chance that you fried the CPU (more risk of that with an AMD than an Intel CPU, Intel does "throttling", which AMD didn't do in most models).

The next step is to boot from a floppy, look around and see how things look, and probaby run chkdsk or scandisk.  Don't be too agressive about actually fixing things right now, that could do more harm than good, but at least find out if they are reporting errors, how many, and what kind.

> It is the CPU fan.  

Is this a Celeron 466 cpu?  A cpu fan not working means your system probably overheated, and the only thing that saved you is the low power requirements of the Celeron.  Normally, you would smell a burning odor shortly after the fan stops.  You may have more damage, like the cpu itself,  if you allowed the system run for an extended period of time.

Hello Lyrk
Please Check this thread:-
https://www.experts-exchange.com/questions/21339621/Sudden-Reboots.html#13478581

I know that its almost a CPU Fan issue, but also trying everything is a good step to the answear.

Can we get a status update on this machine?

I'm personally curious if restoring system files will work.

<< This is urgent for work ....especially over the weekend (I am on call) >>

I don't mean to sound rude, but goodness sakes, if this system is urgent for work, you need to take better care of it.  Never let a CPU fan or a PS fan die, even go slow -- these are just as crucial to cooling a computer as water in a radiator is to keeping your car running.  If you depend on this system for work, I would recommend you do the following --
1. Buy or build a new system running windows XP -- you can do this yourself for $450 or less
2. Make sure you keep copies of all your crucial data on BOTH SYSTEMS, and update it
3.  Invest in a new CPU fan, new PS, and maybe even new CPU-MB for your old system.

Computers these days are as essential as transportation.  In a REAL pinch, you need 2 computers.  There are no if, ands or buts about this.

lol. I think I have 5 Dells in my garage alone.  Agree with ^^^.

Second.
\

Update...........Yes I know... I should take better care of my system..... I do have 2 Computers problem is the other one is down too.   (just don't seem to have the time)

I replaced the fan and it still could not find the Operating System.   I listend for the humming sound of the HD...... nothing....I have 3 other HD and I tried each one.  Same thing it could not find the OS.  

I replaced the cable that runs from the mb to the HD and my cd rw.   Finally it started up (Windows 98).  It gave me just enough time to back up my HD.  Then the system locked up.  

I rebooted the system again and it could not find the OS again 3 times before it recognized the HD.   Then I tried to run some test on it and it locked up again.   It has been 10 minutes I decided to give you an update before it locks up again.  

I have an intel Celeron 466

Now that you have your files. Replace the box. You could go component on it, but with the prices of PCs being at an all time most reasonable, you're probably better to go with a new machine now.

Depending on your hard disk model get the corresponding HDD diagnostic utility and run it on the hard disk just in case its failking which i suspect. Good thing u got ur data off it. Its possible the IDE section of the motherboard might have taken a hit too but i suspect otherwise.

Drive Diagnostics:
http://www.hgst.com/hdd/support/download.htm#DFT
http://www.maxtor.com/en/support/products/index.htm
http://support.wdc.com/download/index.asp
http://www.fcpa.fujitsu.com/support/hard-drives/software_utilities.html
http://www.fcpa.fujitsu.com/download/hard-drives/#diagnostic
http://www.hgst.com/hdd/support/download.htm#DFT 
http://www.seagate.com/support/seatools/index.html
http://www.samsungelectronics.com/hdd/support/utilities/utilities_index.html
http://www.csd.toshiba.com/cgi-bin/tais/su/su_sc_home.jsp

Looks like the rest of ur hardware is in order but just run a memory test from http://www.memtest86.com/#download1

Dan

Can not find operating system occurs when the BIOS cannot locate io.sys. How is that going to help?

I agree with Promethyl if its software issue, you need to use the sys.com command to create a boot on your pc.

What did happen on the sys & fdisk /mbr?

Your hard drive sounds like it is dying, and I suggest that you not use it anymore until you have tested it or tried it on another machine.

All the cards are working.  

sys & fdisk /mbr.  I need another Windows 98 boot disk (it has been a long time since I created a boot disk from another computer.   I will have to find my notes.    

I tried a the restoration disk and it could not find the HD.  It was not until I rebooted over and over did I finally get it to recognize the HD.  It opened into Windows 98 and I was able to use everything.  I even tried to save a test file to the drive.  It acted as if nothing was wrong. (I will not save anything to it until I know it is working 100%).  A couple hours later I tried to reboot the system just to see if it was working.  Again, no OS.

Spoiled computer....It seems like it only wants to read the HD when it feels like it.

I ran a diagnostic in the beginning when it could not find the OS and everything passed except it could not find the HD to test it.  

I will try the drive diagnostic provided by mysticaldan.  

Are HPs know for crashing the HDs?  This is the 4th HD that I have had since 98.  I believe this HD is a Western Digital.  

I will let you know the results.  

Looks like either the IDE cable of the system is gone bad or the Hard disk itself has. I suggest u backup ur data and get urself a new hard disk. Whats happening is that the hard disk is misbehaving. When the circuit works it gets detected and works fine and after that it will work fine.

Usually if u let the system stay on for abt 10 minutes or so and reboot it might get redetected almost at the same time without needing to reboot a million times.

Try and attach this hard disk to another system and see if it works fine. That shud make it sure if the hard disk is fine or not.

Dan

I will try the HD on another computer.  I have 3 spare HD.  2 are still good ...both of them did the same thing as the HD that I have in the PC now.

If it works in another computer.  I try the IDE card.  

And replace cables if necessary.

k

HD works in another PC.  I give up.......   It is working now as long as the HD is the only one on the IDE cable.  Once I add anything else (CD RW, Zip drive, etc) on the same cable or if I move anything in the computer (most of it is all hanging out)  I experience the same problem (reboot reboot reboot...).  

There has to be damage to the mb.  

Next step is to purchase another computer ( I always wanted a laptop anyway).  2nd I will rebuild this one with a new mb.  

Thank You so much for you help while trying to solve this problem.