Computer repeatedly restarts before I can do anything

So this morning, I tried to install Windows 10. At first, it worked! I was all happy, so went on to login. Once I logged into my microsoft account, I was greeted by a blackscreen where I could move my mouse around. so, I rebooted, shift+clicked Restart, and got to the troubleshoot menu. From there, I clicked on "Reset My PC," since it appeared to be the only solution. It rebooted my computer, and suddenly it said something like "Windows restarted or shut down unexpectedly. Please press OK to continue the installation." I clicked OK, and it just rebooted and said the same thing, so I looked up a tutorial, which said to change something's value in regedit from 1 to 3. This sure made the "Windows restarted unexpectedly" go away, but now it just restarts repeatedly, as if it DID pop up, and I pressed OK. I tried multiple things, and I really don't want to send my PC to a repair. Is there any way I can fix this, or do I have to pay for a repair? I'm really stressed out about this, my PC was about 3k$.

Well, I first had to reserve my update by following the steps at How to Upgrade to Windows 10 - Microsoft, then when my upgrade was ready, I installed the update.