Are you ABSOLUTELY sure? If you right mouse click the Command program and Run as Administrator the title at the top the command window should say "Administrator: Command Prompt" . If not in Administrator mode it only shows "Command Prompt" in the title bar. What does yours say?

Well now the fun part I guess . It is time you might consider altering your fault_handler. I'd start by printing out eip and cs to determine what the instruction the instruction pointer was pointing at that caused the fault. You can use the output of objdump (with -D option) on your ELF file to try and match the EIP with an instruction. That might help you narrow down the problem to a particular function.

Other ways of going about this would be trim back your kernel code and see if removing something makes the issue disappear.

Triple faulting where. Before entering protected mode or after? Remember I don't have your system so I don't know so it is very hard to tell. I'd start by simplifying `kernelmain` . Start with something that doesn't do anything but print to the screen (write something to the display at address 0xb8000. Don't use any specialized functions. If that triple faults and causes a reboot then there is likely something before kernelmain is called that is causing the problem. If that works consistently then you can look at adding your other code back into `kernelmain`.

When you say triple faulting does the computer continually reboot? Anyway, it really sounds like to me that writing to the USB hasn't occurred properly. After you write the file with win32disk do you take the USB stick out and move it to another machine? If you do, do you do a safe windows eject before you remove the USB stick? Information on doing that is here: https://www.digitalcitizen.life/how-saf ... -your-data . By default the devices usually use cached writes for performance. When you write to the drive, the data may not have been actually written to the device yet.

As well if you over write the boot sector of a device, Windows may pop up a message about the device being unformatted/unpartititioned and whether you'd like to format the drive. Never tell it to format the USB since that will cause the bootloader to be overwritten.

I don't use win32disk, so I can say anything about it. Did you happen to try using DD after doing the procedure I listed in an earlier comment (a procedure to clean the disk before using DD)? Did it resolve the access denied error?