How to change back to IDE from AHCI?

xStaticX

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Mar 9, 2010
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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 mode....do 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 mode......now 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??
 
Solution
It's actually not that hard to get the OS switched from IDE to AHCI, but the OP needs to get his BIOS set back to IDE first so that he can get Windows booted up. Once he's there, this is what needs to be done (this works for Vista and Windows 7):

1) Run the Registry Editor (regedit.exe)
2) Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
3) Set the "Start" value to 0 (zero)
4) Shut down
5) Start up again, but before Windows boots go into the BIOS configuration screens and change the disk mode to "AHCI". Save the new BIOS configuration and restart so that Windows boots.

When Windows starts, it will detect the change, load new disk drivers, and do one more reboot to start up with them.

Paperdoc

Polypheme
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How to get back should be easy. The system has not written any damaging data to your hard drive. It simply can't understand its data stream this way.

You need to enter the BIOS Setup screen system and make the change there. On most machines, you do this by holding down the "Del" key while it boots up. After a few lines of info in the POST sequence, it will suddenly put you into the opening screen of BIOS Setup. When you do this, watch the screen closely (it changes quickly), often near the bottom. If the "Del" key was the wrong one, you'll see a prompt about which way to enter Setup.

The Setup system is a bunch of menus where you can see and change parameters. There will be prompts on the screen, usually to the right and bottom, about what keys to use to move around, how to change some things, and what your options are. Find the menu page (probably by moving across the top level of tabs) where the SATA hard drives are configured. On that page you will see the ports and at least one, maybe all, will be Enabled. Close to that will be the port mode, usually setable individually for each port. Choices may include IDE (or PATA) Emulation, SATA, AHCI, or RAID. Set your port to IDE emulation as it was originally. Now look at the bottom for the key to Save and Exit - often F10. Confirm and the system will save your settings and reboot that way. Should work smoothly now.

Just FYI, in many places in the BIOS Setup screens there are key settings that can disable your machine and make it hard to recover. There are also lots of place, like the one you just changed, that make a difference but can be changed with no problem and then changed back again if necessary. I generally try not to change anything I don't understand. To help, read your mobo manual. Among other things, it usually will tell you how to recover from a really bad situation by resetting the BIOS to fatcory defaults that work, just so you can get back in to fix things. But you rarely need that - I've never had to. It's just there is case....
 

xStaticX

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Thank you for the reply but here is the problem..........

I can get into the Bios screen but it shuts down after 3-5 seconds so I do not have any time to make any changes. Once the bios screen appears I can press 1 or 2 buttons then it kicks me out and the screen goes black.

I will also contact the manufacturer's tech support since the machine is brand new.
 

Paperdoc

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The behavior you describe does not sound like a hard drive porblem. Just to check, disconnect both the power and data cables to your HDD and try to boot the machine into BIOS Setup. I bet it will behave the same.

What this sounds like is the CPU cooling is inadequate. Typically is the CPU fan is not running, OR if the heatsink is not fastened down tightly to the CPU, this happens. The CPU stats up normally but warms up quickly inside. With no heat removal it soon gets to its upper temperature limit and shuts itself down, and that typically takes 5 to 15 seconds.

Examine your CPU cooling system. See if it seems very solidly mounted on there, or is there some wiggle or wobble to it? If there is any looseness, the heatsink is not fastened down tightly. If that does not appear to be the problem, start up the machine and watch the CPU fan. Normal operation would be for it to come on immediately to full speed, then slow down a little after a few seconds. If it does not run, fix that.
 
It is not easy to change from IDE to AHCI and vice versa without an OS reinstall. The reason is that the sata drivers get loaded early. I know, I had to reinstall to be able to use AHCI to get trim support for a new SSD. Some google search may turn up a method, as I recall, but I did not feel comfortable trying it.

Not being able to stably get into the BIOS screen smacks of a different problem. I think I would return it.



 
It's actually not that hard to get the OS switched from IDE to AHCI, but the OP needs to get his BIOS set back to IDE first so that he can get Windows booted up. Once he's there, this is what needs to be done (this works for Vista and Windows 7):

1) Run the Registry Editor (regedit.exe)
2) Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
3) Set the "Start" value to 0 (zero)
4) Shut down
5) Start up again, but before Windows boots go into the BIOS configuration screens and change the disk mode to "AHCI". Save the new BIOS configuration and restart so that Windows boots.

When Windows starts, it will detect the change, load new disk drivers, and do one more reboot to start up with them.
 
Solution
I dunno if this will help, but I just read a post about this on another web site and it advised to not only set the ...\Services\Msahci "Start" value to zero, but also the ...\Services\pciide "Start" value as well. (Actually, the post said "PSIIDE" but I'm pretty sure that's a typo as there's no such key on my machine).

That's probably just required so that the procedure will work in both directions (IDE -> AHCI and AHCI -> IDE), but it might be worth trying.
 
Nope. Tried again. My PC won't even see the DVD drive if I make those registry changes; it can't even boot off the Windows 7 DVD. Changed it back, and had to do another repair of Windows 7.
Might be time to call the knacker for this Abit IP35 Pro...
 
I feel like I'm missing something here... If you make those changes in the Registry, even under the worst possible scenario it shouldn't affect your ability to boot the Windows 7 DVD. Booting from the DVD is solely a BIOS issue and has nothing whatsoever to do with what's on the hard drive.

Are you saying that it's the BIOS change that's preventing the boot from DVD? When you say "changed it back", are you referring to the BIOS configuration? If so, then exactly what setting did you change and then change back?
 
Yes, the BIOS change prevents booting from my SATA DVD drive. On the Integrated Peripherals page is where the SATA mode is set; it can be IDE, AHCI, or RAID. It only works when set to IDE. The mobo is an Abit IP35 Pro, which has a ICH9R on it.
So yes, "changed it back" refers to the SATA mode in the BIOS.
 
First off, I'd really like to apologize for this thread hijack, even though it's on topic.
Second, I did some searching on this issue, and apparently the Abit IP35 Pro has some BIOS issues with this (there was even a thread at THG). I did not lose my USB keyboard during this process, but the other problems with SATA devices seem to apply. I don't have the final BIOS, just the v17. Since everything else seems to work, and v18 didn't solve this problem, I'm NOT going to flash it; my mobo is an orphan, and support will be sketchy at best. The Q9450 is too competent to toss, but I'd hate to spend money on S775. I'm not sure what I'm going to do yet.
 

bubaii

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Jan 20, 2013
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......
i am useing 2 hdd in my pc , 1st is 80gb and 2nd is 250gb seagate , xp is installed in 80gb hdd, and win-7 is installed in 250 gb, after 2days i found that 250 gb hdd is not working , there was a display on a black screen " hard disk read error , press clt+alt+ del to restart "
when i was trying to repair 250 gb hdd from hiren's boot cd 10.01 , there was a error massage " your hdd is not in ide mode , change it ide mode from achi mode from bios "
when i was trying to change it from bios i found it is already in ide mode. the problem is that i am not able to lode 7 from 250gb hdd.
when 2 hdd are connected with motherboard then there is a booting prblm form xp (80gb hdd) , and when i am running xp the drives from 250gb hdd is not showing ,

please take me out from this prblm
name - bubaii...
 

Johnnys440Charger

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Sminlal, your a Genius. This worked for me. I have a Win7-64 Lenovo M55 -> I switched to a HP Compaq 6200 Pro Intel i5 PC in AHCI mode (I was previously using IDE setting in the BIOS prior to viewing your post). Thanks a million dude. John from Toronto Canada.
 

kghastie

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Apr 27, 2010
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This solves the problem that the OP has, for others (like me) who might be searching for how to switch to IDE from AHCI, but maybe aren't reading carefully, this is may not be the droid you are looking for. This is to switch from IDE to AHCI, not the other way around.

Sorry for resurrecting, but this came up in a search for me so it's still relevant.