I have been bombarded with error messages while booting as of late. A majority of the time the computer won't even boot or about 30 minutes after booting it locks up. Usually it gets stuck right before the XP loading screen.

Some of the error messages that I have received include:

NTLDR is MISSING.

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

A disk read error occurred.

That has been going on for the last two weeks. In a attempt to fix it I opened up the side of the case and checked all of the connections. Shortly after I attempted booting again. This time I got more than one error message on the same screen:

The firmware has detected that a CMOs ChecksumError occurred.

The second message (that I forgot to jot down) said something about the firmware detecting that the date/time was wrong.

Anyway the computer continued to load and when I got to the desktop the date was reset to Jan 1st, 2004. I reset it and then noticed that Windows Security Alerts thought that my anti-virus program was out-of-date. I ran UPDATES on AVG and rebooted, but the message continues to pop up.

So, I am currently on the problem computer. Is there anything I can run, download, etc. while I'm on here (before it decides to lock up again)?

Computer Specs
Windows XP Pro SP3
Gateway E4300
3070MB RAM
Hard Drives: C: - NTFS, E: - NTFS(this is an external hard drive)
Video CARD: NVIDIA GeForce 9800 GT
Antivirus/Spyware/Malware Programs: AVG 9.0 Free, Malwarebytes' Anti-Malware, SUPERAntiSpyware
Windows XP CD: No, my computer did not come with one.1st thing to do is replace your CMOS battery...bout the size of a dime on the MBoard...you will have to re=set all the time settings...
2nd thing you should do is find out who makes your HDD and DLoad and run the FREE diagnostics from the manuf. site...run the long test and let it run to completion...this will take awhile...

Post back with your results.CMOs battery...
Well I found something that resembles a watch battery on my keyboard. However it's closer to the size of a quarter rather than a dime. Is that the same thing or something different?
Also are these CMOs batteries available for purchase in normal electronics stores?

I ran a diagnostic on both of my drives.

The E: drive, a Maxtor Onetouch 4, came up clean.

However the C: Drive, a Western Digital Corporation WD800BD-22JMCO (SATA), can't complete it's diagnostic because of the following error:

The part #on that battery is a #CR 2032...available anywhere...

I'd replace it first ...then re-run the drive fitness test.His drive is bad. Not neccessarily...the BIOS generates SMART info therefore a faulty battery will sometimes show a drive as failing...While Geek-9pm may have got my gender wrong he might be right about the drive. I put in a new CMOs battery and retested the drive. I'm still getting the same error.Run the test from a created bootable CD...there are instructions on the site...
Running the Windows ver. is not always accurate,Well I didn't have any blank CDs so I used a floppy. I received the same error mentioned before from the quick test and the full test gave me a new error.

Error: 0226

Which according to the WD website means...
"Failure to relocate a sector during drive repair. The drive has to be replaced."

So I'm guessing that my hard drive is dying slowly?Yep.

Stop using it immediately and once you have a REPLACEMENT there's hope your important data can be saved...
Post back if you need details...Well, there's not anything important that I absolutely need to save (except for the OS/essentials). I put almost everything I can on my external drive except what needs to be on the internal one.

What should I look for as far as a new hard drive goes? and will I be able to move my OS from the problem drive into a new one or will I have to go out and buy a new OS? (I don't have the XP disks and keys needed to reload it.)If the XP OS was from Gateway, then you can ask them for a replacement CD.
An OEM CD only works properly on the original computer. It will cost a fraction of the retail price. Your product key is somewhere on your Gateway case.