I use win8.1, migrate OS to SSD, after apply and reboot, it can't log into PreOS mode and log into Win8.1 OS directly. Please advise what is the problem? Thank you
If can't enter into PreOS, you can create a bootable media, then migrate OS to SSD from the bootable media.
Click here for creating bootable cd: http://www.disk-partition.com/help/make-bootable-cd-wizard.html