Simple indeed, put the Disk inti\o the tray and restart ur comp and go to the BIOS, in this go to bood configuration and make ur cd drive the 1st boot priority...
Now save and resart or continue...
U will boot...
Else, if not bios, then keep hittin f10 until u get (on sys start ) a menu for boot device..,choose Cdrom...Drive...
Shud be in Q&A