Windows file corrupt/missing

I've been posting on the malware forum because I had to do a system recovery and then got spyware/malware on the computer, had to do another system recovery and wanted to make sure the computer was clean. Just when we were finished doing this, Windows did some automatic updates and then this happened - "Windows did some automatic updates last night while I was sleep and restarted on it's own. I woke up to a message saying windows could not start because the following file is missing or corrupt: <Windows root>\system32\ntoskrnl.exe. Please re-install a copy of the above file." The malware expert had me do a disk check after finally getting it to start again under last known good configurations and the disk check listed over 300 file record segments as unreadable. He thought this may be my hard drive failing but that I should post hear to get guidance on where to go from here. After the last known good configuration restart, the computer was running a little slow and was working really hard (the CPU meter in my system tray was just a green box, indicating it was working at the max). I had to keep closing programs that were not responding. I have an HP Media Center computer running Windows XP with service pack 3? Is my computer dead? What should I do?

Also, after getting it to start an error message came up (and still does):
avast! showed up with an application error for ashServ.exe - The instruction at 0x7e19dda refernced memory at 0x6608a058. The required data was not placed into memory because of an I/O error status of 0xc000009c. Ok to terminate. Cancel to debug.

Also, the computer stays on the black Windows screen when booting a lot longer than it seemed to in the past.

 

To check your hard drive run http://www.majorgeeks.com/HD_Tune_d4130.html
Run the error scan and post your results. Cheers...

 

I downloaded the program you suggested and when I tried to run it I got a Setup Error Window that said "External exception C0000006" and one that said "Error creating window." Ever since this corrupt/missing file message and the last known good configuration restart the computer has had some issues with running most programs I've tried. And when I tried playing a video or something with Windows Media Player the Player would start but would close by itself while trying to connect with the media.

 

How about a repair install with you XP CD.

 

What if I haven't been able to find my XP CD?

 

If your XP Cd was the retail version, you will need to get your hands on another XP CD same version and enter the product key when prompted. Can you locate the key sticker on the PC. Or else use this to get your key.
http://www.majorgeeks.com/download.php?det=2612

If the CD was OEM then you will have to contact HP.

 

OK. Sorry if I'm becoming difficult. But my computer was a display model that already had windows set up and I didn't have to do anything when I got it. It's been a little over two years and I honestly can't remember if I had a Windows XP CD and whether it would be retail or OEM. I do have two disks (DVD) that I made when I first got the computer that say "Recover 1 of 2" and "Recover 2 of 2"...would these disks have anything that I could use? I'm not sure that I know anyone that has a Windows XP CD that would be the same version (I'm not sure how I would know it's the same version). How likely is it that this computer will be able to be fixed? I'm trying to be optimistic but I've done two system recoveries and had this recent problem all in the last week and someone on the malware forum said that this recent problem sounded like the hard drive was failing. I'm feeling a little lost at this point and don't have a Windows CD. Given all of this, what do you think would be my best option?