First please help confirm the following two points:
1. When did the issue begin to occur?
2. Have any changes been made on the computer recently, such as an installation or upgrade?
I know that you are unable to view the current Operation System in Repair console; the issue should be caused by the corruption of the bootloader. Please directly ignore this step and continue with the following wizard.
Method 1: Rebuild BCD
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1. Put the Windows Vista installation disc in the disc drive, and then start the computer.
2. Press a key when the message indicating "Press any key to boot from CD or DVD …". appears.
3. Select a language, a time, a currency, and a keyboard or another input method, and then click Next.
4. Click Repair your computer.
5. (Click the operating system that you want to repair), and then click Next.
6. In the System Recovery Options dialog box, click Command Prompt.
7. Type BOOTREC /FIXMBR, and then press ENTER.
8. Type BOOTREC /FIXBOOT, and then press ENTER.
9. Type BOOTREC /REBUILDBCD, and then press ENTER.
Method 2: Use the Windows Recovery Environment (WinRE) to run System Restore
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1. Insert the Windows Vista installation disc into the disc drive, and then start the computer.
2. Press a key when the message indicating "Press any key to boot from CD or DVD …". appears.
3. Select a language, a time and currency, and a keyboard or input method, and then click Next.
4. Click Repair your computer.
5. In the System Recovery Options dialog box, choose the drive of your Windows installation and click Next
6. At the System Recovery Options Dialog Box, click on System Restore.
7. Follow the System Restore Wizard instruction as usual and choose the appropriate restore point.
8. Click Finish to restore the system.
Method 3: Startup Repair from the Windows Recovery Environment (WinRE)
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1. Insert the Windows Vista installation disc into the disc drive, and then start the computer.
2. Press a key when the message indicating "Press any key to boot from CD or DVD …". appears.
3. Select a language, a time and currency, and a keyboard or input method, and then click Next.
4. Click Repair your computer.
5. In the System Recovery Options dialog box, choose the drive of your Windows installation and click Next.
6. At the System Recovery Options Dialog Box, click on Repair your computer.
7. (Click the operating system that you want to repair), and then click Next.
8. In the System Recovery Options dialog box, click Startup Repair.
Hope it helps!
MCSE, MCSA, MCDST [If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]
