Hello Carl,
That's an excellent way to get CHIRP working. The only problem is that if your radio is a newer one, without updating CHIRP on the CD, you won't have the most recent radios added to CHIRP.
On most of my computers, if I push F12 I get to a screen that says "Boot Options" and I must select BOOT DEVICE ORDER.
I have to arrange the devices so that DVD/CD comes before Hard Drive. Sometimes when you exit, the screen asks "SAVE?" and I say "YES" - it tells you what to press if you want to save. Sometimes it is F10 to save, sometimes it is just a choice in a menu.
Have your CHIRP CD already in the CD/DVD drive.
Then next time you boot, there will be a slight delay in booting - your computer will be searching for the DVD/CD you told it to boot from before Hard Drive and if it's there, you will boot from it.
If you get an error message, open the Computer into Windows, and go to Windows Explorer, or even better "My Computer" and look for the DVD/CD.
Open the device, if you just see just one file but no folders, chances are you just wrote the iso file to the CD instead of using a CD burning application - this page has info on that.
https://www.lifewire.com/mount-burn-iso-windows-8-10-3506971
This page has a picture of what to select, it might be better because you can see the choice "burn disk image" which is what you want to do.
So again do these steps.
Check the CD in My Computer, if you just have one file, you probably burned the iso file to the CD instead of buring the iso image. You'll have to throw away the CD and follow the steps in the articles I've given you.
If you have many files and folders, then you've burnt the iso image to a CD. That's good.
Then go shut off the computer and try different keys to get into BIOS. You can only get into BIOS SETUP for a second or so while the computer boots, you see the logo on the screen, start pressing the F12 or F2 or DEL key repeatedly. Sometimes you have to try it twice because it's a very small window to enter.
Sometimes it is F2, F12 DEL or other key. One computer here it's F2, a different computer requires DEL and this laptop requires F12. Search for the name of your computer and BIOS setup and you'll no doubt find the right combination.
Then change the BOOT ORDER so that DVD/CD is before Hard drive. I put USB first then DVD/CD then hard drive.
Then save the setup, sometimes it's a menu selection, sometimes F10 or other key.
Reboot and then if the CD is good, you will boot into CHIRP.
Hope that helps.
73 David N1EA