Question 1: In this case, the hard disk is broken, you don't need to try to repair it, you can just replace it with a new one.
The reason for this problem is that the voltage is unstable and caused by frequent power failures.
Question 2: This situation can be solved.
Yesterday, I installed the operating system on the POS and found that the same error occurred after installing the xp system twice. Finally, I was going to install the win7 system. After the win7 system was installed, I formatted it again. Win7 system, and then install xp and find that it can be installed again. This is how the problem is solved. Maybe it was caused by me waiting for a while and holding down the Delete key to directly enter the xp installation interface. At first, I thought it was caused by the BIOS, and I was about to flash it. BIOS, after a colleague said that the BIOS of this model could not be found on the Internet, the problem was solved by coincidence, and I was also stunned to ask the reason.