Should still work with DVD or CD. Just to confirm how to boot with the disk.
The software you have is it say operating system or restore CD/DVD ?
1 Put disk in a drive.
2 restart computer.
3 press F12 at boot window (not at window start up.
4 You should have a screen that has options ,boot from onboard CD,usb.
5 High lite the boot from CD.
6 press enter.
7 follow promps for reinstall.
If you have never did a OS reinstall from the disk, you maybe able to restore with a Dell partition that came with the PC.
Simply restart the computer press Cntrl+F11 at boot . And a reinstall patition should come up.
If it still don't work ? Will the PC read a disk in windows