Windows 7 - Windows 7 and my 2nd mobo/cpu swap

I just have to say that Windows 7 is very good with hardware swaps.
I initially installed Windows 7 Ultimate 64bit in August of 2009 with a Q6600 and an Asus P5Q Pro and 8GB of ram.
In November of 2010 I upgraded to an i7 870 and Asus P7P55D-E with 8GB of ram and Windows booted up just fine and ran.
Last week I upgraded to an i7 2600K and Asus P8P67 Pro Rev 3.1 and 8GB of ram and Windows did not boot up. It would start to boot then crash.
I then remembered something I read in the manual about the SATA mode and went into the BIOS and changed the SATA mode from AHCI to IDE and Windows booted up and has been running great since.

I am very impressed with Windows 7 and its ability to cope with major hardware changes.
I "think" I only had 1 Blue Screen since I installed Windows in 2009.

I went from an ASUS M2N68-AM SE2 to an ASUS M4N68T-M V2 with no problems other than switching audio drivers. The M2 was Realteck and the M4 was VIA. Went from DDR2 to DDR3 too with no activation prompt. Windows 7 Home premium OEM. To be honest its not that big a difference in hardware, both motherboards have the same chip-set, but it was still nice that I didn't have to activate again after the swap.

mine required activation both times, but it was over the internet and was quick.

Was your Windows 7 a Retail version? OEM versions are reputed to be more stringent about hardware changes and activation, so I was pleasantly surprised when I wasn't asked to activate. You're not supposed to be able to do what I did with an OEM version. The two motherboards are so close in specs that I guess Windows didn't see enough of a hardware change to trigger activation. I doubt XP would be so forgiving.

My copies are Retail.

OK, thats what I thought. Retail versions give you more breathing room for hardware swaps and your not locked into the first motherboard you activate on like OEM versions. Even if you had to do the phone activation it shouldn't be a big deal as long as that product code is only used on the one PC.