Help!!!

After about 3 tries I finally got High sierra to launch on my PC. i want to try to install mac os on my harddrive so i can launch without USB. I erased the drive but i am not giving the option to change the GUID partition in the drop down menu. "This disk doesn’t use the GUID Partition table scheme." is what I am told when i want to install mac os on the drive. This drive is used so maybe the drive has to be a certain format? Thanks let me know what I have to do in order to install on hdd

submitted by /u/1121345
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