Let me start by saying I'm in Japan, so my computer model and the terms I'm seeing on my PC are all in Japanese, so I might not have the right terminology.
I have an XPS8500 running on Windows 8.1 64-bit that I bought 2 years ago. Today, when I tried to put it into sleep mode, it froze. The monitor shut down, but the PC kept running. After a while, I figured it was just frozen, so I did a hard reset. When I restarted the PC, it gave me the error code 0xc000021a. I tried to run the auto fix, but even after it finished, the computer still refused to load windows with the same code. I tried all of the options in Troubleshooting, but most would not let me run them, just saying it couldn't complete the operation. I tried refreshing, but then it gave me a Disthist.exe error and it won't run. It also won't run in Safe mode.
I am considering doing a system restore to factory settings, but I'm not sure that it will work either, because when I clicked on the option just to see what kind of options it might give me, it still brought up the disthost.exe error, though it allowed me to remain in the restore menu.
i also tried to restore to a restore point, as I read online about other Japanese users who fixed this error code by doing that. However, when I clicked on that option, it said that there were no restore points and could not proceed. This is strange, because I know that I had some. Since disthost and restore points have both messed up, is this a virus that I am dealing with?
Please, any help is appreciated! I'm not so knowledgeable about PC stuff, so please try to give me advice in layman's terms. Thanks!