After a successful NT and programs installation. I tried formatting an unformatted/unpartitioned section of my HD by using disk administrator. This caused the system to crash. After reformatting and reinstalling NT, I get a "missing operating system" message at reboot...

ARe you sure you did not formated the boot partision, what about marking the d or the secound pertiotion active. It the d partition during formatig was marked active, then nt will try to boot from it, this could have happend.

need more information . however , your boot.ini file is corupted most likly which by default is on the first active partition. if you have other operating system on the pc like win95 or 98 ,you should delete all winnt files including boot.ini and reinstall a fresh copy (no update).if you are installing only nt on this pc then make sure you have only one primary active partition. Hope this helps.

Hi, I have faced this problem in my Laptop once.After bugging my head on this funny error" missing operating system",i knocked my laptop from places,as if you knock your toaster when it behaves improperly....and believe me my friend it worked....I concluded that there was some loose connection from inside...."Missing operating system" is no error in the dictionary of NT....Just open up your machine and tighten your nuts and bolts and reboot your machine...If nothing works out replace your hard disk....And once again,this error has nothing to do with OS..... Good luck

I had a similar problem a couple of days ago in my network. The problem was exactly what fazil mentioned above. I fixed it by creating a boot disk by copying the boot.ini, ntldr and ntdetect from my computer onto a floppy disk and booted up the affected computer. I then went into disk administrator and marked the correct partition as active. This fixed my problem. Hope it helps you out as well.