What key or keys do I use to get to the boot menu on start up

What key or keys do I use to access the boot menu on a Acer AX1430g desk top Im trying to recover my password by using CD-ROM with the NT recovery

Usually pressing F10 or F12 [or other Fx key] just as the Brand's logo is fading or has gone off will get to where you can make the choice. Usually there's a couple of lines of text on the black screen that specifies the key for boot choice and for entering the BIOS Setup to make changes. I usually set the Optical drive as the first boot device,.