Standing OS Hardware Upgrade OK?

Wasn't really sure what to title the thread, but here's what I'm doing, and where it's gone so far....

I took my antiquated Core 2 Quad Q6600 / 8GB DDR2 system and am giving it a pretty huge upgrade. Moving to a Sabertooth X79 with a i7 Hexa-core 3690 CPU, and 16GB DDR3 RAM.

Now, so far, I just swapped the hardware out, and then booted Windows. The attempt was to perform this without completely re-installing the OS. I know this wasn't possible with Win7 and prior, but found some optimistic threads about the process functioning fine with Win 8.1.

At first run, it spent about half an hour preparing devices for use. Then booted in on default video drivers, and restarted shortly after I logged in to apply changes.
After the second boot, it restarted again after I logged in, but I didn't see any purpose for it.
At the third startup, it loaded a bit lower than I expected after the logon screen, but got to the desktop and did some poking around. Enough to realize that the MB driver disk isn't readable at all, (not Win10 or hardware related, it's not "seen" on my other PC's either), then the system promptly restarted after about 5 minutes for no apparent reason again.
On the fourth startup, It didn't get to the logon screen, gave an interesting BSOD which was up too short for me to jot the 0x000... code from, and said it was restarting.
On the 5th, I got another BSOD for IRQL_LESS_THAN_blahblahblah, looked like an acpi driver file, but it's been 30 minutes, so my memory could be a bit off. It's one of the most common BSOD messages I see when working on PC's and is typically just a corrupt or incompatible driver file.
On the 5th, it went into recovery mode, said it needs to scan some stuff, and has been at "Diagnosing your PC" for roughly half an hour now.

So, experiment is kind of a fail, but curiosity kicked in, so I'm posting it here. Should I just force a restart and boot from the disk in repair mode, do a recovery install/upgrade, or wipe it all and start over again. (I know I will lose some data in this last process, but at least I made backups before upgrading so it's only a minor setback.)

I realize I'll probably have made a decision and moved with it before I get any real responses to this thread, but I'm really curious if any of you have done this before, or what your opinion is. :)

The problem here is that the OS was configured for a different architecture, chipset, drivers, etc... It cant even read the disk well enough to try to recover.

The first problem is that your old motherboard was probably a BIOS system, while your new board is likely an EFI system. You really need to re-install completely because this needs a new disk structure (a GPT partition, with EFI boot partition, plus reserved partitions. etc..). This is not something that can just be "recovered" from, as the disk partitioning need to be manually changed.

The second problem is that you will need to install the correct kernel and HAL (hardware abstraction layer), and again without having a working I/O subsystem to be able to pull this from an install set, that's not going to work.

It's really going to be a LOT less time to just reinstall.

Yes, old MB was BIOS, and the new system is EFI. I also converted my SATA drives from IDE to AHCI.

Turns out though, the entire issue the whole time was a mis-configured DRAM clock Apparently I poked a setting I should have left alone when doing the initial setup. After flipping that back to normal, system runs just fine. I was running into issues trying to re-image it and went poking around in the "BIOS" settings when I saw the clock speed for the RAM was set higher than the CPU can work with well. bumped it down to 1066 for now. It was at 1866. I will likely try putting it at 1600 later, but want to play stable for a while first.

So, I would have been up and running last night instead of this morning, and the only "issue" with that drastic change to the system was having to re-activate Windows and install a few drivers.

Currently my only issue is the inability to install the Asus AI Suite II due to a detected compatibility issue. So I'll miss out on some monitoring software and a couple system tweaks till I find a workaround for it. No biggie.

I had just ONE favorable experience, with taking a Windows 8.1 hard drive, formatted and installed on an old Desktop PC and putting it on a newer desktop PC. The only thing common to both PC's was that they both had AMD Athlon processors.

After installing the HD on the newer PC, and booting up, I got a message that the OS was installing the new hardware. After a few minutes and a reboot, the little PC was running normally. In many years of working with PC's and many different OS's, it's the first time I've ever been able to move a HD from one PC to another, and have it actually boot up and run. Amazing!

But that's the exception, to the rule, that "you cannot move a HD from one computer to another, unless the hardware is identical."