Steve,
Could you please clear something up for me (that you said in an earlier post):
both computers can talk to computer A if A is not plugged into the router.
If Computer A is not plugged into the router, then how do the other computers communicate with it?
nwprovau.dll......................NWLink IPX/SPX/NetBios...
If you still have this entry in your Registry (and you can't locate the file in your LAC Properties), then that means you must have Uninstalled/Removed it incorrectly. If you are positive that you do not need any sort of Netware connection on your computer, and you can not locate NWLink IPX/SPX in your LAC, then you can remove this registry entry.
(*Note: Before you remove this entry, please create a Registry Back-up).Run LSPFix.exe again, however this time check 'I know what I'm doing' and then select the nwprovau.dll file, and press the right arrow (>>) to send it to the Remove section. Scroll down and click 'Finish>>'. Restart your computer, and test your Connection.