I tried adding that into my CentOS-Media.repo, and then when I tried to apply updates again this is a brand new error message I'm getting:

Sorry about troubling you guys about this, but It's been frustrating me for a while that I just can't seem to get my updates to apply, and being new to Linux it's even more difficult to figure out what's wrong, so I appreciate all the help you guys have given so far.

Ops... maybe I did not explain well. I was talking about two different things: 1) try the yum command directly from a terminal:
this will skip the media repository and let you proceed with the task (check-update in my example).

2) To do that permanently, that is without specfying the --disablerepo option every time you use yum, edit the file /etc/yum.repos.d/CentOS-Media.repo and add or change the line with the enabled flag to

Thanks for the advice! I set the enabled line to 0 and tried a yum update and everything seemed to go fine, so I think that it's all fixed. Not sure why it was buggy before, but thanks again for the help.

EDIT:

Spoke too soon. I think most of the updates were installed, but at the very end after installing I got this error message from the terminal:

I think that just means everything else installed except for this update, which didn't install because there were no active mirrors. I hope this isn't a bad thing, though...

Well, it looks like you've enabled the CentOSPlus repository, at least during the OS installation. I don't remember exactly when and how the installation process asks you to install additional repositories, but maybe you've enable both the DVD media and the CentOSPlus repo. Anyway, look at /etc/yum.repos.d/CentOS-Base.repo and see if the [centosplus] section looks like the one shown here (except for the enabled=0 that should be enabled=1 in your case). Looking at a mirror of centosplus, the packages kernel-2.6.18-92.1.18.el5.centos.plus.i686.rpm and kernel-headers-2.6.18-92.1.18.el5.centos.plus.i386.rpm are in place.

Anyway, before proceeding take a look at the actual kernel installed:
and see if it really is the centosplus version.

When I ran that in the terminal, this is the response from it:

So it looks very similar to what you said, meaning I have the right kernel? I edited the yum.repos.d file and changed enabled=1 to enabled=0 where the file said [centosplus]. I assumed, based on your description, that's what you wanted me to do.

Yes. But I'm still not sure if you have the centos plus version of the kernel. Looking at the output of the uname command, there is nothing telling you have centos plus, but to be sure (please, be patient) can you see the actual kernel package installed?

Here is the output from when I entered the command in the terminal as root:

Not sure what this means... but hopefully it's good news, haha.

Ok. It simply states you have three kernel packages installed. The kernel actually running on your machine is the most recent one: kernel-2.6.18-92.1.18.el5 (as you can see from the output of the uname command). The other two are older versions previously installed. They are kept from the update manager for backup purposes: when you update the kernel, if something goes wrong you can easily switch back to a previous working kernel.

Anyway, regarding your issue it looks like you don't have the CentOS Plus version installed, so that you can safely keep the CentOS Plus repository disabled. To summarize, the problem was simply some erroneous configuration of the available repositories. I hope it's solved, now!

I just tried another yum update and I didn't get any errors, so I have to say I think I'm all set! Thanks for all of the help guys!