Please Help me~~~~Un-identified Trojan in my computer, eating my Hard Disk space

So my computer Hard Drive have been eaten away by virus from 66% down to 36% currently without installing anything.

My hard Drive is IDE (not sure which UATA type is it)
Totaly hard drive size: 74.52GB
C 38.09GB (before virus I had 66% empty space, now I only have 36%)
D 18.55GB
E 17.88GB

I check Virtual Memory size, which was normal 768MB~1.536GB
Hard Drive Indexing was normal
and System Backup was closed.

I also went to Control Panel --> Adminastrative Tools --> Service
running services.msc I notice the process "npkcsvc"
C:\WINDOWS\system32\npkcsvc.exe after searching online info, it says that this is a [Trojan-Downloader.Win32.Agent] from INCA entertainment.
---Note: INCA entertainment is a anti-hacking company for Maiet, Gunz gaming, so I am not sure is this a mistake, or it is an actually virus.

(note: I am not using english Window OS, I am using Window XP Professional 5.1.2600
[Service Pack 2])

So I use AVG AntiSpyware, AVG AntiVirus, Avira AntiVir, Spybot Search and Destroy
--only AVG AntiVirus found 2 trojan
(note both of these are """keygen""", and they have no affect on previous Window XP system)
Trojan horse VB.CSK
Trojan horse PSW.Generic5.AFkD


The virus created 4 folders in the directory: (C:\Documents and Settings)
LocalService, NetworkService, Adminastrator, RECYCLER [note that I didn't create ANY users at all]
---I was unable to delete 3 of these folder (LocalService, NetworkService, RECYCLER) even in safe mode, because the process were running.
---I also attemp to end the process by force by using "Process Explorer v11.11" provided by Microsoft, but apparently they weren't shown in the process section

this was the "Process Explorer v11.11"
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx


Also, how do you backup Registry?


Below is a report from System Repair Engineer 2.5.16.900
from this site: http://www.kztechs.com/eng/download.html

 

Maybe something's wrong with your hard drive. A member had the same problem and the culprit was his failing hard drive. I forgot who he is and I can't find his thread.

Try cleaning your temp files, prefetch, etc with this. Also please defrag. Problem fixed?

I doubt this is the work of a trojan (killdisk wipes the whole drive). You probably have a nasty worm. To be sure you're clean post a hijackthis log here.

EDIT: Your problem is quite similar to DVD+R's. Please check out his thread.

thanatos

 

Check also how many disk space is currently reserved for system restore. Go to start,right click on my computer choose properties,press on the system restore tab,click on settings,the chance is high that the slider is set to the right side. So that can explain why so much space has been used without installing software. Put the slider to the left and press on ok so you will reduce the space used.