From personal technical experience, if your chipset brand/model is the same or similar, you won't have to do anything in order to swap HD to another board/system.
But if your previews board has e.g. VIA chipset, and the new one has INTEL, you'll never boot, you'll keep getting BSODs. Although, I'm not sure it will happen to Windows 7, at least it happens to XP and Vista.
The workaround to that is as it was for the previews OSes:
Before you remove the disk from the old motherboard, goto
Device Manager and expand your
IDE ATA/ATAPI controllers. You will find inside several listings like for example:
ATA Channel 1
ATA Channel 2
etc..
Intel 82801G Ultra ATA Storage Controller <-- this is the key to your problem
You should uninstall the
drivers for your
IDE ATA/ATAPI Controllers before you transfer your HD to the other motherboard.
I also advice you to go to System Devices and delete/uninstall everything regarding your chipset...e.g.
Intel PCI Bridge or VIA PCI Bridge etc. This method is 99% guaranteed that you won't need to reinstall/repair your OS after moving your disk.
Of course, with computers you never know so...good luck