First - I can't locate that motherboard - so I DLd the manual for a GA-M61PM-S2 - nearest thing I could find...
On the 'Advanced BIOS Features' page of your BIOS, 'First / Second / Third Boot Device' should be set to, respectively: 'CDROM', 'Hard Disk', & 'Floppy'; then, when you boot, you should get a prompt, similar to 'Press any key to boot from CDROM...'; if this doesn't happen, write down what is being shown on-screen just prior to booting, and post back...