How can I change back to IDE mode after accidently going to AHCI ??

I purchased a brand new PC and it arrived yesterday. I plugged it in and during the load screen it said something like "your sata is running in IDE you want to run in IDE or AHCI mode", I chose to leave it in IDE mode. I got to the desktop and downloaded some updates, then re-booted. After the reboot, it posted the same comment during loading and I accidently chose AHCI it won't load or anything. It will only allow me to go into Bios for a few seconds and kick me out to a black screen.

Any ideas how to easily get back to IDE mode??
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  1. Best answer
    If you can't get into your BIOS to reset back to IDE, you'll probably need to clear your CMOS. Depending on your board, you'll either have a button on it to push or else, it's a jumper setting.

    Refer to your motherboard reference manual for more information on that.
  2. in all actuality you should reformat and keep it in ahci mode if you can you will get better performance out of your hard drives that way. but if not what type of mobo do you have and what model is it
  3. No. No. Don't reformat. If you can get back to IDE mode after clearing your cmos, all you have to do is boot back up into Windows in IDE mode. If you want to go to AHCI mode, then all it requires is you modify a registry entry, reboot, go into your CMOS and set the SATA mode to AHCI and you're all set. I just did this last night.

    This Microsoft support article tells you what registry setting you need to change:

    Don't reformat! You don't have to!
  4. Thank you for the replies.........

    No, I do not want to format. I just want it to work in either IDE or AHCI mode :)

    Currently, I can get into the bios but it shuts down after 3-5 seconds so I do not have time to make any changes. I will try clearing the CMOS first and hopefully that will work.
  5. huh never knew about that... i always just reformated lol
  6. @isamuelson.............

    Clearing the CMOS solved the problem. After the CMOS was cleared it allowed me to go in and change the Bios back to the original IDE settings.......Thanks !!!
  7. Best answer selected by xStaticX.
  8. xStaticX said:

    Clearing the CMOS solved the problem. After the CMOS was cleared it allowed me to go in and change the Bios back to the original IDE settings.......Thanks !!!

    That's what I was hoping would help. Now, if you still want to run in AHCI mode (I don't think you'll see a difference in performance - I didn't), just follow the instructions I pointed you to.

    On another note, is it still asking you if you want to run in AHCI mode when you boot up? I wonder if there's a BIOS option to turn that off? I would find that annoying after awhile.
  9. there is a performance increase though its only on read right speeds. so essentially the only things you will see a boost in is the initial loading of software and booting of windows.
  10. Yes, it asks me every boot up if I want to keep it in IDE mode but it does have a "count down" to automatically say yes. I will search around in my BIOS and see if there is an option to turn it off.

    If I only see a boost for loading software and booting of Windows then I will probably leave it in IDE mode. I will do some more research though to see if it would be beneficial to go to AHCI mode. I think for what I use my PC for that it really wouldn't help me.
  11. Related question, if I may:

    Reading the KB, it appears that changing this registry param allows for both AHCI and IDE mode drivers to load at Windows startup, rather than changing which driver Windows will boot off of. Now, in the case where an installation was performed as IDE, but there is (perceived or not) need to switch to AHCI mode: Does this actually enable the OS to run in AHCI mode? Or is it just that both drivers are now loaded at startup?

    An example where this would be needed is to enable TRIM support on a SSD upon which the OS was was installed in IDE mode. (TRIM does not work in IDE mode....)

    {Edit} - Found a Tutorial on the topic, and it appears that YES - By doing this, the OS will now run in AHCI mode.
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