My Intel Board DG41RQ beeps once at start up and after that it comes up with the Intel screen. After that it beeps once again and then starts to load the operating system.

The beeps are post during post the very first work is done by the ram,all the memory in the ram is first transferred to the hard disk,and remains active untill turned off.
make sure that your RAM is securely seated
test or replace all the leads that attach to your hard drive make sure the connections are secure including electrical extensions + IDE,SATA the ones that attach from your
((motherboard to hard drive))
make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty or just replace them they are probably old and faulty ?
hope this helps