It's been a while since I did this and I never documented it for myself. So here it is and for anyone else that comes across this.

1. You will need an ISO of Windows, doesn't matter if it's 10, 11, 2012, 2016, etc as long it's Windows with the Repair my computer option in it
2. Boot from the ISO and onthe language/keyboard selection windows click Next and then click Repair my computer on the bottom left of the window
3. Select the Troubleshoot option
4. Select the Command Prompt option
5. Type in D: and press Enter (could be a different drive letter depending on your setup, so try C: or E: as well) 
   To make sure you have the right drive, enter the dir command see if it the contents are the same as the C:\ drive
6. Enter cd Windows
7. Enter cd System32
8. Enter move utilman.exe utilman.exe.bak
9. Enter copy cmd.exe utilman.exe
10. In case your default administator account is disabled, you need to enable it with net user administrator /active:yes
11. Restart the machine
12. Once you are back on the login screen, use the shortcut WIN+U or click on the accessibility icon on the bottom right. It will present you with the command prompt
13. Enter net user Administrator <new password here> and then close the prompt
14. You can now login as administrator with the new password

To revert the changes you made, simply restart the machine and boot into the ISO again and into the command prompt. 

1. Type in D: or the drive that is attached to the windows drive
2. Enter cd Windows
3. Enter cd System32
4. Enter del utilman.exe ren utilman.exe.bak utilman
5. Restart the machine

I've also encountered that the troubleshooting tool will not detect the windows drive at all and this is because the tool didn't map it. 
You can check this and map it by doing the following:

1. When inside the command prompt, type in diskpart
2. Enter list disk and take note of the disk that has the OS installed
3. enter select disk <number of the disk with the OS>
4. enter list vol and take note of the volume that contains the Windows install
5. enter select vol <number of the volume> 
6. enter assign letter=<drive letter you want to use> 
7. enter exit, you are now done and you should be able to access the OS drive now