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.