Wierd error on Vista boot after installing Windows 8.1

[Antoniu_1]

A couple of days ago, I installed Windows 8.1. But I discovered that I needed a GPT HardDisk. So, I converted it using AOMEI's partition program. I checked to see if Vista still boots and it was fine. After the install of Windows 8.1, Vista refused to boot, giving this: http://imgur.com/GcHCRoj.
If I choose 'Start Windows normally' it gives me this: http://imgur.com/p9EGEBj. If I choose to launch startup repair it gives me status 0xc0000225. Why and how can I fix this?

 

[dualcoremax]

It seems that the two operating systems cannot find their original boot records due to the file type conversion.
read this article https://www.partitionwizard.com/partitionmanager/dual-boot-windows-7-and-windows-8.html

 

[dualcoremax]

if you have a vista CD/DVD, try to boot form the disk and use repair options like startup repair.

 

[Antoniu_1]

I tried to repair it with Windows 8.1 disk. It found startup problems, but it couldn't fix them because the OS (Vista) installation is "locked". What does that mean and how do I unblock it? And that link didn't help.🙁

 

[Antoniu_1]

What if I remove Windows 8.1? Would Vista be bootable?

 

[dualcoremax]

sorry for the late. i can't exactly say it. but keep trying.
Try to find a vista CD/DVD and boot from it then select repair your computer. this will make boot loader to default state