Re-using the HDD depends on the type it is IDE or SATA and the types of slot that the new MB has, the Blu Ray player will depend on your new case but it should not be a problem with a modern case.
Please see my canned speech below regarding your operating system;
Just a cautionary note, unless your OS disk is the full retail edition you cannot use it with a new MB as an OEM disk is tied to the original MB it was paired with, to use an OEM disk with a new MB is software piracy and therefore illegal.
Exceptions to the above are 1: If your MB is replaced under warranty and 2: If your MB is replaced out of warranty with an alternative type but same brand due to the original model no longer being available, an upgraded MB however will require the purchase of a new OS licence.
Microsoft can waive the above and quite often do if you contact them first as this makes it apparent that you are have acted honestly.
Can I ask where you got the free Windows 7 upgrade from.
Do not worry about doing the build on your own as there are plenty of us here who will guide you step by step and there are tutorials for you to also study.
courtesy of Troy and Artellos and http://www.geekstogo...rface-material/