What you need to do is enter the BIOS and change the boot sequence first, see below;
To change Boot Sequence in your BIOS (for installing a new OS have your boot disk in the drive read).
Reboot the system and at the first post screen (where it is counting up memory) start tapping the DEL button
This will enter you into the BIOS/CMOS area.
Find the Advanced area and click Enter
Look for Boot Sequence or Boot Options and highlight that click Enter
Now highlight the first drive and follow the directions on the bottom of the screen on how to modify it and change it to CD/DVD drive.
Change the second drive to the C or Main Drive
Once that is done then click F10 to Save and Exit
You will be prompted to enter Y to verify Save and Exit. Click Y and the system will now reboot with the new settings.
Once you have done this you should be given the option to do either a quick or full format using NTFS and select a partition including the size of the partition, I always do the full NTFS but the size of the partition depends on the OS and the storage capacity on the HDD.
This should help
http://www.top-windo...hard-drive.html