Changing the motherboard under Windows 7

Today I needed to swap motherboards between a machine running Hyper-V Server 2008 R2 and another running 32-bit Windows 7. No need to go into the reason in detail; it’s to do with some testing I’m doing of Hyper-V backup and restore. The boards were similar, both Intel, though one had a Pentium D processor installed and the other a Core Duo. Anyway, I did the deed and was intrigued to see whether Windows would start in its new hardware.

Hyper-V Server – which is really 64-bit Server Core 2008 R2 – started fine, installed some new drivers, requested a restart, and all was well.

Windows 7 on the other hand did not start. It rebooted itself and offered startup repair, which I accepted. It suggested I try a system restore, which I refused, on the grounds that the problem was not some new corruption, but that I had just changed the motherboard. Next, startup repair went into a lengthy checking procedure, at the end of which it reported failure with an unknown problem possibly related to a configuration change.

That was annoying. Then I remembered the problems Windows has with changing to and from AHCI, a BIOS configuration for Serial ATA. I posted on the subject in the context of Vista. I checked the BIOS, which was set to AHCI, changed it to IDE mode, and Windows started fine. Then I made the registry change for AHCI, shutdown, changed back to AHCI in the BIOS. Again, Windows started fine.

What puzzles me is why the long-running Windows 7 startup repair sequence does not check for this problem. If the alternative is a complete reinstall of Windows, it could save a lot of time and aggravation.

It is also worth noting that Windows 7 declared itself non-genuine after this operation, though actually it re-activated OK. I guess if you had two machines with OEM versions of Windows 7, for example, and swapped the motherboards, then strictly you would need two new licenses.

2 thoughts on “Changing the motherboard under Windows 7”

  1. I had a motherboard die on my Win7 machine last week and much the same scenario happened. Mine was 64-bit but I don’t think that played into it.

    I did know about enabling MSAHCI.SYS and had done that. Startup Repair took 20 minutes before failing which I interpret to mean it could not find the problem and assumed it was a bad driver by default.

    Eventually after two more boots and one in safe mode I got it running, though I did have to activate by phone and briefly got the non-genuine Windows warning.

    Next step would have been to try booting into the Win7 PE on the install disk. I didn’t think I would have to reinstall again even though I did have a image backup.

  2. I recently Changed from an ASUS M2n68-LA to an ASUS M2n68-VM as the 68-la had died on me.. I installed The M2n68-VM and short of a few driver issues it worked like a charm without needing a Fresh install of Windows 7 Ulamite x64 OEM version.

    It is my edcuated opion (as I am not a Service tech..but planning on beeing a support tech) if the old motherboard and the new motherboard are practiclly the same make and Model.. shuch was my case… the instal of the motherboard should go off without much of a hitch. But if you are changing a full system then logicly you would have to reinstal the OS..

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