I am new to Linux so please bear with me. I burned a (small) CD from which to boot a Debian O/S and altered the BIOS to select the DVD/CD for start up. Each time I tried, however, my laptop (a Compaq Presario CQ56 ) booted up Windows 7. The ISO file I downloaded and burned to disk was amd64 as the laptop runs on an amd 64bit processor. Could anyone suggest what might be the problem? I should explain that I wish to try a Linux O/S out of interest at this time and I am not too keen on having two operating systems on the hard disk until I have had experience with Linux. Thank you.