I'm clueless about Grub and having issues with CentOS6.6 that is installed on the box. It also has Windows 8.1 installed. I want to reinstall CentOS to version 7, but want to insure I don't wipe anything, and the bootloader remains as is, but includes the new CentOS installation. How do I go about this? I've been unable to locate some good details on how this works. Thanks!
In case you do not know yet:
You cannot upgrade from CentOS 6.x to CentOS 7.x. You'll have to perform a replacement of OS.
CentosOS 6.x has Grub legacy. CentOS 7.x has Grub2. They are not the same. You might not get away without learning how these two bootloader work so you can translate what you have in 6.x to 7.x
Thanks for the response.
I was able to recover the CentOS 6.6 filesystem, by tossing in the 6.6 disk and selecting to upgrade OS and update Grub. Once I bounced the system, it loaded just fine.
Now, the dual boot Win 8 partition/disk from the Grub menu, doesn't boot. Any ideas what needs to be done to fix the problem?
The error:
Windows Boot Manager
Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:
1. Insert your Windows installation disc and restart your computer.
2. Choose your language settings, and then click next.
3. Click "Repair your computer."
If you do not have this disc, contact your system administrator or computer manufacturer for assistance.
File: \Boot\BCD
Status: 0xc000000c
Info: The Boot Configuration Data for your PC is missing or contains errors.