|You have not provided enough information for us to be able to troubleshoot your problem(s).|
Supply the details of the things you tried and what the result was!!!
Did you make sure the boot order in your bios Setup is set correctly to boot from a bootable CD in an optical drive?
See the second and third paragraphs of response 3.
Were you able to boot the CD?
Have you tried other CDs that you know are bootable to see if you get the prompt "Press any key to boot from the CD" or similar while booting??
Are you SURE the CD you are trying to use is a Recovery CD, with which you can reload the orginal contents of C, along with the intact and un-altered original data contents of the second partition on the original hard drive??
Brand name system computers these days usually DO NOT come with a Recovery CD - you're supposed to make that, and/or a Recovery CD set, yourself by using a Dell supplied program, while Windows is working well enough to use the program(s) - but they may come with a brand name CD with drivers, etc. on it.
I searched on eBay for Dimension 4700 recovery CD, and Dimension 4700 CD, and so far all I have found is this, a disk with drivers etc. on it:
Is the CD you are trying to boot with the same or similar to this one?
If it is, you cannot restore your system with it, and it's probably NOT bootable!
Is the bios Setup recognizing the optical drive you have the CD in?
Are you getting any error messages?
According to "hits" on the web, your Dimension 4700 could have originally come with XP Home, XP MCE 2002, or XP Pro.
I assume you're still using the operating system it came with, and you have not loaded Windows from a regular CD (or DVD) - is that correct?
Dell Dimension 4700 Series Service Manual
Amongst other things including onboard video and a PCIE X16 slot, your motherboard has a single IDE header, and two SATA headers.
According to "hits" on the web, a Dimension 4700 often comes with two optical (CD or DVD) drives as well as one hard drive. Therefore - at least one of them must be a SATA drive.
Is your hard drive IDE or SATA?
Do you have two optical drives installed?
Is the optical drive, or are the optical drives, IDE or SATA?
If you don't know, or aren't sure, tell us the model numbers of your hard and optical drives that are listed in Device Manager.
Did the computer come with, or have you installed, a PCI-E video card?
If it didn't come with a PCI-E video card and you installed one, you often have to upgrade the power supply as well - otherwise you are likely to have problems and the power supply may fail because it is being overloaded frequently - brand name systems often come with a minimal capacity power supply that can't handle video cards with recent video chipsets.