have a viao computer that has win Vista

[shashgo]

Whenever I turn it on, the first screen that pops up says "operating system not found".  The computer is about a year old maybe year and a half.

Does this error mean the hard drive is busted, or could there be something else thats wrong with it

[patio]

You have 4 or 5 Topics going now...are all these issues the same machine ? ?

[shashgo]

no different machines , Im trying to get educated while fixing some machines

I  was at the vaio website and it says that this error can be caused by a non compatible video driver.  Here is what it says

You may experience the following problems on a Windows Vista-based computer that is using an NVIDIA nForce 430/410 (also known as MCP 51) Southbridge chipset:

    * When you start the computer, no operating system is found. Additionally, you may receive an error message that resembles the following:
      No Operating System (OS) Found
      This problem may occur even though the computer has been operating correctly for some time. For example, the computer may have been operating for hours, for days, or for weeks. When you examine the NTFS file system boot sector, the NTFS boot record may have been moved by a multiple of 4 bytes.
    * Random data corruption may affect any files on the computer.

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CAUSE
This problem may be caused by multiple-queue "read and write" operations that o...
This problem may be caused by multiple-queue "read and write" operations that occur at the same time. The data in a given sector may be randomly shifted by a multiple of 4 bytes. However, the sector itself is not changed. This problem may occur on the boot sector or may affect any file on the computer. For example, the problem may affect the following types of files:

    * picture files
    * image files
    * movie files
    * data files
    * encrypted files

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RESOLUTION
If you are using an NVIDIA nForce 430/410 Southbridge chipset, we recommend that...
If you are using an NVIDIA nForce 430/410 Southbridge chipset, we recommend that you avoid this problem by installing a driver update for the device. To do this, visit the following Microsoft Web site:
http://windowsupdate.microsoft.com (http://windowsupdate.microsoft.com)
If your computer is affected by this problem, one of the following driver updates will be listed on the Windows Update page:

    * NVIDIA Corporation driver update for NVIDIA MCP61 Serial ATA Controller
    * NVIDIA Corporation driver update for NVIDIA nForce 430/410 Serial ATA Controller
    * NVIDIA Corporation driver update for NVIDIA nForce 590/570/550 Serial ATA Controller
    * NVIDIA Corporation driver update for NVIDIA nForce4 Serial ATA Controller

The driver update is listed as an optional update and has a publish date of 3/5/2007 or a later date.

Alternatively, contact NVIDIA to obtain a driver update that resolves this problem. For information about how to contact the manufacturer of your hardware, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base:
65416  (http://support.microsoft.com/kb/65416/ ) Hardware and software vendor contact information, A-K

60781  (http://support.microsoft.com/kb/60781/ ) Hardware and software vendor contact information, L-P

60782  (http://support.microsoft.com/kb/60782/ ) Hardware and software vendor contact information, Q-Z
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

I have a question:  How can I possibly update the driver if the computer doesnt boot up.  All I have access to is the setup screen (the BIOS).  how do i access the drivers

[patio]

Carry on then...

[Broni]

LOL.

[patio]

Have you tried booting to safemode ? ?
Tap F8 repeatedly after powering up and before any splash screens...

[shashgo]

I tied to do that, but nothing happens.  The computer proceeds on to give me the vaio splash screen and then the error operating system cannot be read.  Maybe the disk drive somehow is jolted loose, let me try taking out the drive and putting it back in.  and ill try the f8 thing again. 

ill  post what happens

is there anything else I can try? 

One thing about manufacturers: They dont sell the os disk with a computer but rather put the OS on a separate partition.  But what is the use of all that if the computer wont boot up.  They should just give the disks with the computer I think.