Start up PC,,, before it reaches to the desktop, press your delete key or F1 key or pending on your motherboard funtions to access the bios menu.
It will take you into your bios menu.
From there look for the boot setting category.
Find your hard drive model# then disable the hard drive.
What that does is when you reboot your PC and have your copy of your opperating system in the dvd drive, your computer boots from the dvd drive first. You then see it say on the screen boot from cd/ dvd and then click the enter key.
Since your hard drive is disable, the PC goes directly to the bootable cd thats in your drive and reads from that source.
Once you have master that method, The opperating system software will now take over directing you on how to continue with setup.
Very simple from there, you'll have to posibly do a few clicks about network settings, your time zone and your serial key. PLUS the oppertunity to partition your hard drive thats where you will want to pay closes attention to where you install your opperating system.
Your c: drive is where you should install to, but you get the chance to split up your hard drive into local drives such as
c: drive d: drive and so on.
I reconmend as an example on a 250 gb hard drive, create 175gb on c: drive and use the remaining gb space for d: drive.......
It will reboot once or twice, when it does just allow it to continue with setup.DO NOT press any keys while it reboots and continues.
Once you are now finally at the home stages in the install, you'll have a chance to create a user account, and few other timbits.
When you finally have access to your desktop, reboot and go back into your bios menu and enable your hard drive once again.You should be good to go. Just prepare to update your settings for the desktop.