Hi,
It's still a remainder of your trojan, and your computer is right: c\windows\ststem\ doesn't exist.
Take a look at the following excerpt from the HackFix article:
First, click Start, and go to Run. In the box, type regedit and click OK.
When regedit starts, you will see a file-like tree on the left hand panel. Open the folders to follow the path:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
At the end, click on 'Run' once, and the right hand panel should change.
On the right hand side of Regedit, look for the item titled
Loader = "c:\windows\system\***"
The *** will be a random .exe name. Write this down as it is the sub7 server!
Right click on that line only and choose delete.
Last, open the folders to follow the path:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
At the end, click on 'RunServices' once, and the right hand panel should change.
On the right hand side of Regedit, again look for the item titled the same as above.
Right click on that line only and choose delete. Close regedit and reboot your PC.
Close RegEdit and use Windows Explorer to open the file c:\windows\win.ini
Near the top you will see a line starting with run=
If you see a path pointing to the sub7 server here as well, delete it so the line Only reads run=
Save and close the win.ini file, then open your system.ini (also in the c:\windows directory)
Look for a line starting with Shell=explorer.exe
If the Sub7 server name is after this, remove that file name so the line reads exactly shell=explorer.exe
Save and close system.ini.
Follow up the tips in this article, and see whether anything remains in the locations indicated.
Details may vary, but any line starting with loader= in your RunServices key is to be deleted.
And make sure that the run= and load= lines in your Win.Ini are also empty, or at least don't contain anything suspicious.
Finally, if that doesn't help, search the registry by keyword 'ststem', and remove it, if found.
You could also search your System.ini and Autoexec.bat.
Good luck,