Trying to Repair Windows XP.

I have an old emachines T1100 that was working fine until a few weeks ago, when it abruptly restarted and came back with this message:

Windows could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM

Then it says I can try to repair it with the 'original setup CD-ROM". To my recollection, XP was already installed when I got the PC, and I don't remember having a startup disc. If I did, I have long since lost it. I was able to find my emachines restore CDs, but they only give me the option of 'restoring' windows XP and erasing everything from my hard drive.

I have already tried chkdsk and restoring from a previous configuration, to no avail. Is there any way to repair windows without losing all my stuff? Where do I get the right setup CD?

I guess this exactly is the error you facing:

http://www.troublefixers.com/wp-cont...le_missing.jpg

Well FYI, possibly the cause for this is corrupted Registry. The only way to get rid of this issue without loosing is Repairing the system. But yeah, you need the Installation CD for the same that you have lost. What you can do is borrow any Windows XP Cd from your any friend and try with the same. If it wont work or you get stuck for the product key than the only way is to format the entire system (that make you loose all your stuff from the C Drive) or you need to take to customer support.

For more info about how to repair or some more info on the same, you must check out this:
http://forums.techarena.in/guides-tutorials/1106716.htm

So I downloaded an iso of Windows XP Home (because I assume that's the edition that came with the PC) and burned a setup CD. I put it in my old PC and followed the prompts listed on many sites. Supposedly I should come across a screen that says "If one of the following XP Installations is damaged, setup can try to repair it."

But I don't. Instead, I end up on a screen that shows existing partitions and unpartitioned space, and my only option is to set up a new windows XP on a partition (which i don't have enough space to do). So now the question is, why isn't my PC finding the Windows XP that is already installed?

Another update:
I tried another route and chose the option saying "To repair a Windows XP installation using recovery console, press R."

According to every website I've read, once I enter recovery console I should get a prompt to select the windows installation I would like to repair. But once again, my screen shows something different. My screen just gives the option of exiting recovery console by typing 'exit', and underneath that I get this:

C:\>

That's it. No windows selection, no prompt for an administrator password, nothing.

There are hundreds of websites on how to "repair" windows XP, yet none of them coincide with what I see on my screen. This is getting really frustrating.

Hey All!
Well you really have a serious problem the thing you have to do is very simple and you will get rid of this problem.
As you have mentioned above that you already have create a CD of windows XP. You don't have need to install a fresh copy of Windows, Make sure that CD you burn is bootable.
Insert your Bootable CD/DVD in the CD/DVD room and follow the instruction.