Your computer fails to boot which has Vista as the operating system. You suspect that the problem is the hard drive, but you aren't sure. What can you do to prove that the problem is indeed the hard drive?

A. Install XP on the hard drive and attempt to boot.

B. Boot into Safe Mode by hitting the F8 key.

C. Boot up into a Windows Setup DVD.

D. Move the Primary Drive jumper and reboot.

To determine if the problem lies with the hard drive, you can follow the steps below:

1. Start by trying option B. Boot into Safe Mode by hitting the F8 key before the Windows Vista logo appears during startup. This will load Windows with only the necessary drivers and services, bypassing any startup programs or drivers that might be causing the issue. If your computer boots into Safe Mode successfully, then the problem might not be related to the hard drive.

2. If option B doesn't resolve the issue or your computer still fails to boot, you can try option C. Obtain a Windows Setup DVD for the version of Windows Vista you are using. Insert the DVD into your computer and boot from it by changing the boot order in the BIOS settings. This will allow you to run the Windows Setup utility, which can help diagnose and repair issues with the operating system. If your computer fails to boot from the Windows Setup DVD, it could indicate a problem with the hard drive or other hardware components.

3. If both options B and C do not provide a solution, you can consider option D. Moving the Primary Drive jumper and rebooting is only applicable if you are using an older computer with an IDE (Integrated Drive Electronics) hard drive. This action can help you determine if the hard drive is faulty or not, as it temporarily changes the drive's configuration. However, keep in mind that this option is less common for modern computers that use SATA (Serial Advanced Technology Attachment) hard drives.

4. Option A, installing XP on the hard drive and attempting to boot, might not be necessary in this case. Reinstalling a different operating system may not effectively diagnose the problem and could potentially cause data loss if not done correctly.

In summary, options B and C are the most common and recommended methods to diagnose issues with a hard drive, while option D is less commonly used. Option A is not necessary and may have unwanted consequences.