Defect mobo, OEM Windows 7?

Call Microsoft directly, and explain your situation.

I have done this many times before, and Microsoft has always re-started the OEM for me.

TIP: Sometimes an identical MoBo Model isn't 100% identical at the component level, new BIOS, new IC's etc., and MS knows that. But please remember, you must be 100% honest with MS.

OEM editions of homestead windows 7, as quickly as Activated, are tied to the 1st computer they're popular on, and, can never be put in on yet another computing device. Retail fashions, even though, is additionally popular on another computing device, even though, only after being eradicated from the previous computing device. So, the actual question is: Did your computing device incorporate W 7 pre-attached on it. if it is the case, RTFM, and burn your man or woman W 7 restoration DVD, and stick to the person consultant to return your computing device to "production unit-New" situation. there is not any could desire to spark off W 7 whilst put in from a W 7 therapeutic DVD.

You said, "So now I've got the mobo replaced, but no OS.".  Connect the hard disk and verify that it's correctly detected in BIOS.  Set the boot sequence with the hard disk as the first boot device.

Assuming that you were not booting from a RAID array, verify that the no SATA controllers are set to a RAID mode.

In the SATA configuration, set IDE emulation mode if that's what you had used previously, otherwise select AHCI.  If you don't know which to use, select either one and attempt to boot.  If the boot fails, select the other mode.

Note that it is probably necessary to connect the hard disk to the same SATA port as before, otherwise the boot loader will be looking to a controller that has nothing connected.