Can.t get bios to keep cd rom as 1st.boot option

I am trying to set the bios so the cd rome is frist boot option.I hit f2 the bios comes up i move arrow to boot dev. hit enter. says to select boot dev.with arrow up or down key,i have 3options,1st ,removable dev . 2hard drive dev.3atapi cdrom dev. says to press enter ,use arrow to select cd rom.,hit arrow to hi lite it.it says to hit f 10 to save and exit. i have done this a few times but it go.s back to the same as it was. and will not boot from the cd. the only thing that may be wrong is i can.t mov it up to the top.i tried diffrent keys , it stays at 3. i hop you can give some help on this.i hope i posted this in the right forum.Thanks x bill a noob at this.

If you can getto the bios after hitting F2 or F12 key?
If you could get to the bios,then the matter is simple and the rest is all easy.

Enter Y when savin the BIOS data…