Return of the Computer's booting problem

[AdvancedK47]

stupid title

Ok. Here is the thing:

I was running Windows 7 and Windows Vista in the same disk in different partitions. I wanted to extend Vista's GB room so I decided to change the Active drive from Vista to 7 but it refused to have the option Extend. So I turned off my computer and forgot to change the active partition back to Vista and when I turned it on the next day:

BOOTMGR is missing
Press Ctrl+Alt+Delete to restart

I was like wtf. Very similar to my last problem. So I decided to replace 7 with Vista hoping that would do the trick. But it gave an error a bit after starting the installation.

It happened every time I tried to install. And when I tried replacing Vista with 7, it refused to boot the disk and gave the same BOOTMGR message after the BOOT FROM DISK

So I tried Vista to 7 again, and it refused to load the disk like 7 to Vista.

So then I tried XP to 7 because my ROM hacking files are in Vista but once again, it refuses to boot.

And yes, I have Primary and Secondary boot devices set to CD-ROM. I have no idea what the problem is.

Is there any way to solve this without harming my ROM Hacking and Document files?

[Eureka1]

Could try running killdisk and starting from scratch, most likely solution.

http://www.killdisk.com/

[twocows]

Do a repair installation from your Vista DVD. If that doesn't help, install GRUB.