Kindly I ask your attention.
Well, might be that we need additional information like, Mainboard and BIOS.
Do create a Repair Disk?
Do you have the Original DVD?
Put in and use Windows Repair.https://www.google.nl/#q=Windows+8.1+Windows+Boot+Manager+freezes+during+loadinghttps://www.google.nl/#q=Windows+8.1+says+%22Preparing+for+Automatic+Repair%22+then+black+
Hopefully I let you known enough, that you will find the answers you seek!
Good luck and have fun doing it!