Ongoing BSOD code 0x0000007b (INACCESSIBLE_BOOT_DEVICE), mobo swap

I want to try everything possible before doing a clean W7 install.

The system is Windows 7 (64-bit). I had a problem, either the CPU or the motherboard died. I have a new mobo+CPU now (Asus B85M-G with Intel I5-4460). Previous hardware was MSI 770-C45 with Phenom X6 1090T.

After I turned on the PC with new hardware, it powered up correctly, but W7 had a blue screen of death (BSOD). It wouldn't go to safe mode either. It suggested that I might want to perform an attempt to repair, which I did. It didn't help. It might have been my mistake, because I connected hard drives in wrong order (so it had a different letter).

Now the drive is connected correctly, with the letter C: (as previously). The attempts to boot Windows end up with BSOD. Safe mode and any other mode has the same BSOD. System loading stops at CLASSPNP.SYS and has the BSOD code 0x0000007b (INACCESSIBLE_BOOT_DEVICE), many forums and tutorials suggest that CLASSPNP.SYS is a red herring and actual culprit is the SATA/IDE driver.

Repair doesn't work.

I can boot from the Windows installation DVD. I attempted to install the system on the existing instance of Windows, but installer wouldn't detect it. It suggests to make a clean install (which I have to reject for now).

I can enter the command prompt from the Windows DVD.

I attempted to perform SFC /SCANNOW, but it says there is an ongoing system repair that needs to be completed after rebooting. If I reboot and attempt to complete the repair, the repair software will say that it cannot be completed.

I tried BOOTREC /SCANOS, it finds C:\WINDOWS as an existing install.

I tried BOOTREC /FIXBOOT, it says "Element not found".

BOOTREC /FIXMBR says operation successful.

BOOTREC /REBUILDBCD finds C:\WINDOWS, but after I try to add this install it says "Element not found".

When I try BCDBOOT C:\WINDOWS /v, I get the "BFSVC: Failed to get system partition! Last Error = 0x3bc3".

More ideas? Should I try the forceful option of BOOTSECT?

It doesn't matter whether SATA mode in BIOS is set to AHCI or IDE NATIVE or IDE LEGACY, all versions give the same effects.
I also tried DISKPART to set the system partition as active (some tutorials suggested it), it didn't help.

I created a bootable USB drive with famous Paragon Rescue Kit 10, attempted to repair it automatically (many people say it helped). It didn't help.

I also tried the fix_7hdc.vbs script. It ran correctly, but it seems that there was a "No change" comment in all instances it tried to fix, so I guess it didn't really make any changes.

I also tried to edit the registry. I loaded the actual registry branch and turned off any suspicious "SCSI Miniport" drivers from "Start" value 3 to "Start" value 4. I left ATAPI.SYS, PCIIDE.SYS, INTELIDE.SYS.

I still get the BSOD. More ideas?

Final solution: after all this funny stuff instead of trying normal boot / repairs / whatever, I should have chosen "LAST KNOWN GOOD CONFIG" from Windows boot options.