I need help enabling AHCI in Windows 7

SickBeast

Lifer
Jul 21, 2000
14,377
19
81
I've tried changing the registry setting and then going into my BIOS to enable AHCI, but then Windows won't boot and says "BOOTMGR is missing". Do I need to boot the Windows DVD and do a recovery of some sort? I'm surprised it isn't just working for me. Am I doing something wrong?

If any of you have experience with this and can help me out I would really appreciate it.
 

SickBeast

Lifer
Jul 21, 2000
14,377
19
81
That's not the error message I'm getting and I've already tried that solution and it's not helping at all. Thanks for trying though. :)
 

Rifter

Lifer
Oct 9, 1999
11,522
751
126
I ended up reinstalling windows when i tried this. The reg trick didnt work for me either.
 

postmortemIA

Diamond Member
Jul 11, 2006
7,721
40
91
strange, that message means more or less that no partition was found on drive. bootmgr file is usually placed on C:\
Are you sure that your first drive is still one that system boots from? it might changed in BIOS when you switched to AHCI.
 
Last edited:

Black-Wolf

Member
Dec 27, 2011
32
0
0
I went through this after a bios update which changed my boot priority. Make sure it hasn't been changed. Also, there is no bootmgr in Vista or 7. In XP just reset defaults in the bios.
 

stargazr

Diamond Member
Jun 13, 2010
4,176
3,715
136
Is this a fresh install? If you load Win 7 with other drives attached, for some reason the boot files might go on another drive.
 

SickBeast

Lifer
Jul 21, 2000
14,377
19
81
strange, that message means more or less that no partition was found on drive. bootmgr file is usually placed on C:\
Are you sure that your first drive is still one that system boots from? it might changed in BIOS when you switched to AHCI.
You're a genius! That is indeed what happened. Thank you very much for the tip. I was getting really frustrated. :)

Thanks everyone for your input.