Guide Step by Step: Understanding the Problem : Your PC is not recognizing the drive with macOS Catalina as bootable. The drive is formatted as APFS (Case Sensitive), but shows as “bootable: no” in macOS Utilities. Bootable Flag and APFS Formatting : The issue may relate to the drive not being flagged as bootable. APFS (Case Sensitive) format is correct, but the bootable flag needs to be set. Verify Boot Mode Compatibility : Ensure that your BIOS/UEFI settings are compatible with your macOS installation. If Catalina was installed in UEFI mode, ensure that your BIOS is set to UEFI, not Legacy or CSM. Use OpenCore Configurator for EFI Partition : Follow the advice of Goodcitizen177. Use OpenCore Configurator to access and modify the EFI partition on your SSD. Copy the EFI folder from your installation USB (which has a working bootloader) to the EFI partition of your SSD. Making the Drive Bootable : Boot into macOS Recovery or use a bootable macOS USB. Open Terminal from the Utilities men...