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Miss Operating System error: need help!

ny971181 asked
Medium Priority
Last Modified: 2012-06-27
hi, I am building a second hand computer. Once I connected every hardware and cables, I turned on the computer, after Ram detecting and the table of hardwares appeared, there was a error msg: Missing Operating System. So I reinstalled MS-Dos, but once I restarted computer, same error. What is the possible cause for my error? Please help, this has been killing me all week!

Any suggestion will be greatly appreciated

Chris Lee
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Infrastructure Specialist
Check with fdisk to see if your partition is active!

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I don't know much about partition. Could you tell me a little bit more here? I will check the book myself also. and how to use fdisk? please tell me more detail so I can start trying it as soon as possible. thank you very much and have a nice day!

Chris :)

Fdisk is very simple to use. (But be careful cause it can make a lot of damage as well if you delete the wrong partitions and so on.) You can boot on your MSDos install disk and exit installation directly then type 'fdisk' at the promt. Then you will enter Fdisk

What you probably need to use option '2' to activate your primary partition.
You can use option '4' to show the partition information on the current HD There you can check if and wich partition is active under status. (Look for the 'A') it shold be your primary (PRI DOS) in normal cases.

Options 1 and 3 is used to make and delete partitions.

If you have more than one physical disk in your system then you have an Fifth option '5' too change the curren HD to administrate. Here you will se a quick resumé of all your disks (If you are using scsi they might not show up here)

Well start Fdisk an look around It is easy to use.

HenrieInfrastructure Specialist

I've got nothing to add, Yin said it right.

Good luck ny971181 !

PS. Tell us if you need more info.



I took a look at the fdisk last night. they are what you tell me here. I didn't do anything b4 I get comment for you, tonight I will try option2 which will activate the partition. I am excited now.

Could you tell me what it will do activating partition. I mean what does that mean?

I will grade you answer once I finish :)

you said it all right. but I wish I can give you some points too.
thank you.

I think I will still have questoin on this problem.



hi, that doesn't work.  I chose option 2, but it said The only startable partition on Drive 1 is already set active.
What can I do next?

HenrieInfrastructure Specialist

Try the following:
start with your Dos-disk and go to the A:\ prompt. Type SYS C: and reboot again.

If this doesn't work, up the points some more and I'll email you a utility for checking your partitions and bootsector.


That still doesn't work. my email is CALPRCR@AOL.COM.


This may be a simple problem with the disk prameters not being set properly in the (bios) setup. especialy if this is a disk that was working on a previos computer.
If your setup has AUTODETECT - use it.


  You are right, the disk was used in another computer b4. In Bios Setup I chose autodetect hard disk and saved it. but what else can I do in autodetect ? I still got the same problem.

HenrieInfrastructure Specialist

Sent you an email with proggie and comments,

let me know,


that is useful.


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