Backdoor.Tidserv reported in pciide.sys

Norton popped up on my wife's computer saying that it had detected the Backdoor.Tidserv rootkit.  We followed the instructions which included downloading and using a removal tool from http://www.symantec.com/security_response/writeup.jsp?docid=2010-090608-3309-99.  That tool, fixtdss.exe, tells us that the offending file is system32/pciide.sys.

 

Isn't that an important file to my system?  If I allowed Norton to remove that file, I think that I'd have major problems.

 

I checked the web and found that most pciide.sys files are the same size as the one I have.  I'm nervous about leaving the file there and I'm nervous about removing it.

 

Any suggestions?