The easiest way to check if a Disk uses GPT or MBR Partition would be to do it from the Disk Management window. If you are familiar with the Windows Command-line interpreter, you can use either ...

Many high-end games, professional software, and cloud security applications now require Secure Boot and TPM 2.0 features, which are only supported when the system disk uses the GPT partition format.

Okay, I was completely confused about your setup. You kept mentioning SSDs and HDDs and never mentioned a 250GB SSD specifically, and weren't clear about what drives did what. I thought it was just ...