Question Windows 11 needing two drives to boot up

Feb 26, 2023
Hello! I have a pre-built PC that came with Windows. The 1TB drive(C: ) containing the OS was formatted in MBR, and it doesn’t let me change it to GPT (for upgrading to windows 11). I got a second drive (256 GB) formatted it in GPT, and cloned the 1TB onto it (along with the same system files). Now my pc refuses to start up unless both drives are connected.

I’m planning to get a new drive (2TB), and want to reorganize to have the OS on the 256 GB drive, games on the 2TB, and everything else on the 1TB. How can I move the OS without having to completely erase and repurchase it? Thanks in advance!
You can't. Not really. You have a borked installation and you need to start from scratch by disconnecting ALL drives except the drive you want Windows on and doing a clean install to that drive, after which you can reconnect your other drives and then completely remove all partitions from them after backing up any important data elsewhere temporarily (Or permanently, as a point of backup for that data), and then creating a new healthy partition on that drive for the storage of the data you wish to retain permanently on it that is not part of the OS or does not belong on the OS drive.

Before doing the actual Windows installation you will want to make sure that all UEFI options are enabled in the BIOS including Secure boot and TPM/fTPM settings and that CSM (Compatibility support module) is disabled.