Since January of this year, we have been troubleshooting this error message at bootup: "Operating System Not Found" has been causing the system to have to be powered on and off several times before it would finally boot up to Windows; very annoying. Many troubleshooting methods have been applied. Some include performing a full system recovery including reformatting the hard drive, installing a new C drive, inserting a new cmos battery, connecting a new ide ribbon cable to the C drive, etc.) These methods would work for some time, but after a short period of time, the same error message would start again. We finally ended up with the following setup not by choice but by trial and error. We were just trying various options of connecting the drives in hopes to get rid of the problem. For now the following setup seems to be working with no problems. If the current setup is working, as it is said if it ain't broken, don't fix it. However, this could be a temporary fix like the rest have been. Currently my drives are setup as the BIOS shows them: On the same ribbon/ide channel: Primary Master = DVD rom Primary Slave = Zip drive On the same ribbon/ide channel: 2ndary Master = C drive 2ndary Slave = D drive We switched the IDE cables of the drives but did not change and drive jumpers. We really did not know that switching the IDE cables would result to the current setup. We have mostly heard that the booting C drive should be connected to the primary master channel with a slave drive as being a cd or dvd or or zip, or another harddrive, etc. 1) Would like to read other opinions about this setup in regards to if the above setup may eventually fail or become unstabled or cause other problems and what type of problems or if this setup is acceptable if no problems occur or noted? 2) Since there are two IDE channels using seperate ribbons, does it really matter which ribbon the C drive, having the operating system, is connected to as long as it is in the primary position on that ribbon? Thank you.

hello normaly c: is master on primay ide chanel. if its working fine as secondary . and continues to work there that tells me two things. that the chanels were roung in the first place. or that the primary chanel has a problem.hard ware or driver. or bios setting. i seam to rember that the primary has resource priority. i could be roung. if any thing the new set up might be slower.but slow is better than not running.

I would have put it:- Primary Master = C drive Primary Slave = D drive 2ndary Master = DVD rom 2ndary Slave = Zip drive And made sure both IDE's where enabled in the Bios the detected drives or set them all to Auto.

Os not found relates to the bios going to the first track of the disk and trying to mount the OS. I would expect this if you are changing the bios settings for the drive. But the fact you have changed everything and now it works tells me it's your motherboard ide primary controller. If that mb is under warranty I would RMA it. It isn't what is connected via primary vs secondary channels but what the mix is on the ide cable. Slower devices like cdroms/dvd/tape drives should be seperate from hard drives. Reason is the bus goes to the slowest device. Kinda wastes that 7200rmp ATA100 drive being being connected with a ata33 device like a cdrom.

You left out a lot of detail, like system board information, processor type, type of IDE cables, type of drives, etc... By chance is it an A-Bit board? Is the cable for the IDE drives the correct 80 wire cables not the older 40 wire cables? Are the cables shorter than 18 inches long? Is the Master plugged into the end of the IDE cable? Did you try enabling the power on memory test so as to allow the drives more time to power up?

WARLOCK, We had everything setup just like you do and have the same as you do. which worked fine for about six months. Then "operating system not found" started. January of this year. Each time we call the manufacture tech support for help, they continuously tell us our hard drive is DEAD as if there could be no other problem. We do not feel that the hard drive is the problem or is dead, because the system has been having this problem, randomly, once or twice a month since January of this year. Sometimes one or two poweroffs and back on will allow the system to boot to Windows and work fine. We did not tell the manufacture, we changed the hard drive ourselves to see, because it would void our warranty. We do not believe it is the hard drive. Finally, as the last resort among various efforts to correct the problem, we tried switching the IDE cables by changing them on the hard drives, now the drives and everything seem to be working fine so far -- it's only been about a week. This was exactly our setup: I would have put it:- Primary Master = C drive Primary Slave = D drive 2ndary Master = DVD rom 2ndary Slave = Zip drive And made sure both IDE's where enabled in the Bios the detected drives or set them all to Auto. --------------- wawadave, What you are saying sounds more on target of what it could be, a problem with the motherboard ide primary controller. With the backwards connections, i.e., C drive as secondary master, D drive as secondary slave, etc., there does not seem to be any degrade in system performance and system appears to be running fine at this point. For how long this setup will function like this is unknown, but if it continues to work problem free, then it can stay like this. But, as the next method for troubleshooting, what you are saying about the motherboard ide primary controller will be highly considered. The whole computer system is still under warranty. The problem is since the manufacture is so set on troubleshooting the hard drive like this could be most likely the only problem, I don't know how we could inform them that we already changed the hard drive and still the problem exist. If we tell them this, I think our warranty will be voided altogether, which I have about another year and a half to go. Maybe they will continue to help with some issues that we might need assistance with if everything continues to work like it is setup. On the other hand, if the problem occurs again, we could re-set up everything back the way the manufacture would accept it and let them come out and change the hard drive and see for themselves that this is not the problem. Then we will see what they would want to do next when the problem occurs again. ------------ JackG, I did not include all the specs because I have been doing a lot of research on this problem and have found no resolutions from many who are experiencing this. This problem exist with different operating systems, hardware, and configurations. So, it appears that it really does not matter what the specs are that you mentioned. As the matter of fact there is a lot of people expressing this problem, right here, on computing.net. Do a search on "operating system not found". By chance is it an A-Bit board? Don't know about this. It is a Phoenix MB Is the cable for the IDE drives the correct 80 wire cables not the older 40 wire cables? Are the cables shorter than 18 inches long? The computer was manufacture custom-built in June 2001. So, I would imagine it would have the correct wire cables. Is the Master plugged into the end of the IDE cable? I would think so since the system has been booting to Windows and is now. Did you try enabling the power on memory test so as to allow the drives more time to power up? No, this was not thought about. By default, the system is set up to QuickBoot, which worked fine for six months after purchasing it. --------------- Thank all of you for your help. Will read and consider any other information contributed to this thread. Everyones assistance is much appreciated. Thank you, thank you.

Download a program called PC Check SE. It installs to a floppy disk. Put the PC back to how it should be and use the floppy disk as a boot disk. You can use it to run all sorts of test,s:- Drives, motherboard,memory, keyboard,mouse. etc. hope this helps you figure out what is wrong.