iPC Stop sign

[Lazorith]

Alright I finally got a program that actually INSTALLS!!!! YAY, but once I boot from the drive with it installed It acts as if its booting and after about 20 secs of being on the apple screen it dims and there is a stop logo over the apple and goes no further. Also is there an easier way I can pick which HD to boot from besides me going into BIOS and changing the order?
Again many thanks