I have built several computers before and have always used new hard drives. However I was building a new PC for myself and giving my old one to my younger brother and I wanted to take the hard drive out and transfer it to the new computer. As I have always used fresh hard drives I was wondering if this is possible without disrupting initial BIOS setup or if i have to manually transfer files to a new HD using a transfer cable.
Acronis (True image) is a great program - I've relied on it for many years.
Daft question - are you looking to simply connect your old boot HDD into your new pc (new mb/etc) and hope that all will be fine at boot? - can be done but only for the very experienced (there's alot you'll have to manually do later e.g. correct driver issues). I'm not sure if Acronis can do these corrections automatically (I'd be very impressed if it did. Email them to confirm).
If, on the other hand, you plan on installing the OS in your new pc to a new hard drive (always the best way for a new mb) but wish to have access later to your old HDD, then no major problems (you'll need to remove the old OS install at some point).
At this opportune time, have you considered an SSD for your OS? Around 128GB min will allow you your OS plus some of your most frequently used programs. You will also be able to use your old HDD for data and extra programs.
The os is on this disk? Then you will most likely don't get it to work, because the chipset of the new mobo is different. You can try it, but if it gives you trouble, don't wast the time and re-install the os.