Hey there, sorry if this is out of place as I'm unfamiliar with the forum but I'm at a loss here. I'm not great with computers and ordered a prebuilt, which was supposed to have Windows 10 pre-installed, but as far as I can tell, it was not. On startup it detected the SSD I have installed but did not list it as an available boot device and just left me to mess around in BIOS settings. I went ahead and set up a USB in order to boot from so I could install Windows, but now I'm getting a message saying that I cannot install Windows onto any of the internal SSD partitions because they are all MBR and need to be GPT.
I'm very wary about using what's build in to the Windows installer to reformat because it's saying it will lose data. This is a brand new PC and I have no idea what sort of system files I could lose by reformatting and I don't have anything with which to back them up available (and wouldn't know how to do it without an OS installed). I looked around on the internet for some tools I might be able to use, but everything I found seemed to have guides for reformatting when Windows was already installed, and again, as far as I can tell it never was. I'd really appreciate any advice on how to proceed and let me know if there is more info you all need. Thanks for any help you can offer!