Tip: If you are unclear about internal structure of computer, please do not operate at random, because even a slight mistake may cause more serious damage. Supposing the Missing Operating System error appears due to unsteady connection, the hard disk would appear in BIOS again after reconnection, and then Windows might be bootable. Then, take apart computer and reconnect hard disk steadily. If you are capable of taking out hard disk and then connecting it correctly, please quit from BIOS and power off computer. At this time, different users should take different measures. Now attention: If no disk is shown up or system disk isn't here (shown as ' None' or ' Not Detected'), we can say BIOS doesn't detect the drive. In BIOS please find these or similar items: IDE Primary Master, IDE Primary Slave, IDE Secondary Master, etc. Usually it is F2, F10, Del…However, different computers or motherboards require different keys, so you'd better search on the internet or you can consult your computer manufacturer to get the correct key. Start computer and press a specified key to enter BIOS. If you made dust clean or your computer suffered heavy shock before the Operating System not Found error appears, it is necessary to check whether the hard disk is detected by BIOS. As a result, all files including Windows OS saved on the disk will be inaccessible. If the system disk isn't recognized by BIOS, it cannot be used to read and write data. And the following 5 solutions are introduced in this order. Actually, they had better start with checking hard drive for hardware failures and then deal with software issues since the latter should be done on the base of correct hardware condition.

Since multiple issues can lead to the error, most users do not know how to start the repair. Let's see details.ĥ Solutions That May Help You Get out of Missing Operating System Error Fortunately, for each cause we have the corresponding solution. If one or more of these 5 issues are true, users will receive the disturbing error message Missing Operating System or Operating System not Found.

The partition which saves Windows boot files is no longer active or users set wrong partition active.

Windows Master Boot Record (MBR) located on the hard drive is damaged or corrupted.

Users make improper or incorrect BIOS settings.

The hard disk failed either physically or logically.

The basic input/output system (BIOS) does not detect the hard disk that installs Windows.

In general, both hardware issues and software failures can make an operating system not found, and here we mainly list the following 5: 5 Causes That Lead to Operating System Missing Tip: Depending on the BIOS used by system, the error message could also be ' Operating System not Found'.

Please install an operating system