You mentioned having a cercsr6.sys file dated 12/13/2004.
For what it's worth, here's the file information on my copy of CERCSR6.sys (with the same date):
[Actual] Size: 38.9 KB (39,904 bytes)
Size on Disk: 40.0 KB (40,960 bytes)
Created & Modified on Monday, December 13, 2004, 5:14:00 PM
File version: 4.1.0.7405
Description: DELL CERC SATA1.5/6ch Miniport Driver
Copyright: Copyright 2003 Adaptec, Inc. All rights reserved
Intertal name: cercsr6.sys.B7405
Product name: Dell RAID Controller
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Furthermore, I verified that my copies (in the two separate subdirectories) were identical. You can do this as follows:
Click on START, then RUN, and in the "open" box type COMMAND and hit OK. That should open up the "DOS" COMMAND.COM prompt. Very carefully type-in the following line
fc c:\windows\system32\drivers\cercsr6.sys c:\windows\dell\cercsr6\cercsr6.sys /b
and hit ENTER. If it responds with "FC: no differences encountered", the two files are the same (even if they have different times/dates).
[You close the command prompt by typing in EXIT then hitting ENTER. ]