Win7 x64 does not boot after changing SATA mode

Hi all,

So I was messing around with my bios settings and I changed the SATA mode on the SATA controller from AHCI to IDE for some reason. Now the computer does not boot, it simply hangs when the BIOS tries to initiate the boot sequence.

I spent some time reading through problems like this on the forums, and I tried using my windows 7 installation disk to initiate an automatic repair. It goes as far as to recognize the windows 7 installation but when I try to start the repair process it says "cannot select startup entries" or something like that and cancels itself.

I also tried using the command prompt in Windows RE and using bootrec /fixmbr and /fixboot, which both worked. However, when I try bootrec /rebuildbcd, it recognizes my one windows installation (so far so good) but then when I select Y to include it to the boot list, it reports "The requested system device cannot be found" and it craps out.

I tried the above in both ahci (the mode windows 7 was installed in) and IDE, just for kicks and the same thing happens. I'm also aware of the registry tweak you can make to force 7 to boot up the sata drives, but since I can't even boot up in my computer I can't see any way I can do that.

Thanks for your time, and for your help in advance.

Try one of these for editing the registry: How To Edit Windows Registry Key Values without Booting in Windows Raymond.CC Blog

thanks alot guys. I'm going to try this bad boy out right now.

Did you try changing it back or reset the Bios to default settings.

If you do not know what you are doing with the bios DO NOT mess with it.

We should make this a sticky with a Giant Font !

But seriously, did you reset the Bios?

Zomby88:

I was so stupid. I knew from previous experience that I should not change the SATA settings, but this time I was trying to flash the ROM in an Xbox dvd-drive and since the machine couldn't detect it, I decided that I should change the mode to IDE and see if that worked. There are two SATA controllers on my machine, but I changed the wrong one (the one with both of my sata hdd's) and not the controller with the drive connected to it. Anyways, here I am. I don't consider myself a windows expert but I think myself as an adept troubleshooter.

Yes, I did change the settings back to what it used to be. I didn't reset the bios cause then there'll be too many settings to change back and besides, i only changed the sata operating mode so there's no use to resetting it. The problem seems to reside in the loading of SATA drivers, because the boot sequence doesn't even work. (The motherboard says "booting operating system....." and then it hangs. Usually the screen's supposed to black out for a fraction of a second and then the trippy windows7 startup animation shows up, but none of this happens.

Gregrocker: thanks for your input, but let me say in advance that i won't be able to do your first suggestion cause I won't be able to boot into safe mode. I already tried your second point, changing the SATA mode to IDE. (and to clarify, I won't be "changing back" to IDE mode as I installed my OS with AHCI.)

EDIT: I didn't read your part on loading the drivers during windows setup. I shall try that out too. Just wondering, shouldn't those drivers be included in the setup disk by default? I don't remember loading any extra drivers during install.....

Also, what do you mean by "click through to Startup Repair to run up to 3 separate times until Win7 starts." I mean, what's the significance of running startup repair 3 times? Please clarify.

EDIT 2: looks like you edited out this paragraph, lol

And finally, I am pretty certain that my partitions are intact. I'm not sure when it said this, but windowsRE was able to report the size and free space of my hard disk, which would suggest that all of the data is still there, right?

thanks again for your time and input peeps. Worse comes to worst, i'll do a new installation on my HDD (without re-formatting,) move all of my important data out, and then do a fresh install. But it would be great if I can just get my computer booting again

Haven't heard of switching to IDE mode from preferred ACHI before - may I ask what was the purpose?

The IDE drivers would already be there, so it likely isn't going to work. Can you change it back to ACHI now? Try running Repair afterward if it won't start.

If the MBR had become damaged, you sometimes need to run Startup Repair up to 3 times as it attempts to repair it first then finally rewrites it. But this is more likely not an MBR issue. Repair may still get it up and running in ACHI again though, and no harm to try it repeatedly.

If you have files needing recovery, then use free Partition Wizard bootable CD or live disk to explore them, shrink existing Win7 to make room for new install, then after install try to browse to files from Win7 explorer. After copying files over, delete old installation and recover space (and if necessary active flag and MBR - mark new partition Active to avoid having to do this later) into new Win7. We can help you do this.

If you have no files to attempt recovery, then wipe the HD using installer Custom>Drive tools then format before install.