Hello all. I migrated my working old OCZ 240gb SSD to a newer Samsung 256gb SSD so I could replace the aging OCZ. After swapping drives, could not boot up with a HDD error. On investigation with Easeus partition software comparing the 2 drives noticed the Samsung was GPT and the OCZ was MBR, so I used the utility to convert the Samsung to MBR. This did not work either. Note the non-bootable SSD is fully accessible as a secondary drive. The Samsung was initially the boot drive in a newer HP Omen desktop and was working normally. Although I have my boot order as USB-CD-HDD, if the non bootable SSD is installed as my boot drive, I cannot boot from either USB thumb drive or bootable CD Windows repair disks. Always get the HDD error. System: Latest Windows 10 on a Lenovo Thinkpad W500 (Old but works great). Question is: how do I boot from USB/CD with a broken but repairable C: drive? Thanks (c: