Are you using the 32bit version of XP, and logged in with an administrator account?
But let's try something else:
Download Pocket Killbox:
http://www.atribune.org/downloads/KillBox.exe
Start Killbox and place a tick next to [x]delete on reboot.
And press the "all files" button. (just above the yellow triangle)
Copy this list into the windows clipboard:
(highlight the text , and select "copy")
C:\WINDOWS\ifiacnnA.exe
C:\WINDOWS\system32\w001bfc1.dll
C:\WINDOWS\system32\ibic03e4.sys
C:\WINDOWS\system32\ibic03e4.dll
Back in Killbox go > file > paste from clipboard,
Click the
red highlighted X button and say yes to the prompt, then click OK.
Exit Killbox, restart your PC, and post a new combofix log please.