Hi Suzy,
Don't worry, we will not abandon you... there's lots of folks here ready and willing to help you. 
It would be a wise move to make sure you have printed out all the directions you need, repeat all of them, before starting the format and clean reinstall of Windows.
I think the problem you have hit is that you cannot boot into the Microsoft Win 7 installation DVD that is in the drive? Is that right?
If that is the case, then its likely that your computer's "boot priority order" setting needs to be altered, and to do that you need to go into the BIOS
A word of explanation about the BIOS... think of it as a mini operating system that operates before Windows loads, it will look and feel very different from the more familiar and more friendly Windows screens, but this is normal. The BIOS will tell your computer which device it should try and use to start itself up. What we want is for the BIOS to tell your computer to try and boot up firstly from the CD/DVD drive before trying anything else.
When you first switch on your machine you may see a message on screen along the lines of:
Press F11 or F12 for boot priority
or Press Del for Setup or BIOS
or press Esc for set up
maybe its F2 on your particular machine
If you don't see that onscreen message then its a question of looking through the motherboard owners manual for the actual keyboard key to use.... you could of course use the trial and error method and try each one in turn until you hit gold....
When you try and access the BIOS sometimes called "set up" its necessary to start tapping (once per second) the appropriate key IMMEDIATELY after pushing the "power on" button, don't wait even for two seconds...start tapping straightaway!
Your computer will then either start Windows normally or go straight to the BIOS, if it goes into Windows (which is what you don't want) then wait until it's fully booted up (usually 2 or 3 minutes) and then close down in the normal way ( full shutdown not a sleep etc) and try again....
When you get into the BIOS, tread carefully, alter nothing other than the "boot priority" setting, it's usually found under "Boot order" or "Advanced Settings"
The boot order you need is:
first .............CD/DVD (sometimes called optical drive)
second....... Hard drive
the rest don't matter, but be careful that the CD/DVD drive selected as the first boot priority device is the fitted or inbuilt CD/DVD drive and NOT an external USB type (portable one)
At the bottom of the BIOS screens there will be menus showing you the keys to press to alter settings and when you are happy with them, there will be shown the keys to press to SAVE the changes and exit ( they must be saved before exiting..... )
When you have done that then the machine should close down of its own accord and then boot into the Win 7 installation disc but often you may see a message onscreen that says:
"press any key to boot from CD"
so immediately press once, the space bar on your keyboard and then the instructions you have should be followed.
Its best to make sure that all peripherals are disconnected from your computer before starting the format and reinstall (printers, phones, memory sticks, external drives, camera cards etc) and if you usually use a wireless keyboard or mouse then replace them temporarily with USB (or PS2 if applicable) versions before proceeding. You can and should leave your Ethernet cable connected twixt your router/modem and computer, if this is how you normally connect.
Good luck....
Regards
paws