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ATA/AHCI Help

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Last response: in Windows 7
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September 1, 2012 11:34:12 AM

Hi,

I bought a new pc recently and it was working as normal until yesterday. I was hoping I could get some advice on it?

Before things started to go wrong, I put the pc into sleep mode as I wasn't using it. I came back around an hour later, forgetting it was turned on, and took the plug out of the wall socket.
I turned the pc back on a few hours later and it advised me to attempt a startup repair, which I did. When it finished it said something like 'cannot fix this problem' and in the feedback it said 'startup repair offline'.

The next option I tried was a system restore. The restore worked successfully but the pc still couldn't get past the boot screen (At this point I noticed a quick flash of the BSoD during the boot).
I then tried to use the command prompt to run a few other tests/repairs. I ran "chkdsk" and found no bad sectors. I also ran "sfc /scannow" and was told that 'Windows Resource Protection could not start the repair service'.

Before I was ready to give up for the night, I tried to start the pc in Safe Mode which again didn't work but it did show that it was getting hung up when trying to open/find the file "classpnp.sys".
After searching for "classpnp.sys" on forums I tried one of the recommended solutions, changing the hard drive from "IDE" to "AHCI" in the bios.

This worked!! :wahoo: 

I know a little about computers but not enough to know if this is a permanent or foolproof solution.

Should I just use the computer as normal with it set to "AHCI" or should I take the pc back and get a refund/replacement in case these problems return?

Thanks

Windows 7 Professional 64-bit
System Model: Gigabyte H61M-S2PV
CPU: Intel Celeron G540 @ 2.5GHz
Memory: 4GB

More about : ata ahci

September 1, 2012 11:51:15 AM

I think that you'll be fine now, but if you don't want to risk it, then reset it to how it was and take it back.
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September 1, 2012 11:58:06 AM

I'm going to say permanent, though I'm not sure how the value got flipped.

ATA or IDE mode is what the hdds of old used. Big flat grey cables, both the hdd and controller "spoke" ATA. AHCI is the newer standard. SATA, little red cables, advanced things like TRIM and NCQ. The drivers for these modes are different. As you found out you can't just go in and change it. If windows is loaded in AHCI mode and the controller is changed to ATA, then it won't boot. Windows will use the driver it was told to use and they are not interchangeable. Only by going into the bios and changing it back can you fix it.
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September 1, 2012 1:12:32 PM

Best answer selected by charger29.
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September 1, 2012 1:14:40 PM

4745454b said:
I'm going to say permanent, though I'm not sure how the value got flipped.

ATA or IDE mode is what the hdds of old used. Big flat grey cables, both the hdd and controller "spoke" ATA. AHCI is the newer standard. SATA, little red cables, advanced things like TRIM and NCQ. The drivers for these modes are different. As you found out you can't just go in and change it. If windows is loaded in AHCI mode and the controller is changed to ATA, then it won't boot. Windows will use the driver it was told to use and they are not interchangeable. Only by going into the bios and changing it back can you fix it.


Thanks, It seems that by turning it off wrong it changed from ATA to AHCI and I had to change it back again. I guess I wont be turning it off like that again.
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