This might help, Phil. Found it
here.
Looks like you need your Windows CD though.
TIP #19: When attempting to install Internet Connection Sharing, I get the following error message: 'Netconn has caused an error in Netconn.exe'.
1) Try finding Netconn.exe in your C:\Windows directory and double-clicking it.
2) If the error still occurs, delete Netconn.exe
3) Next, click Start, click Run, type MSCONFIG (hit enter)
4) Click the Extract File button
5) Type in NETCONN.EXE as the file you would like to extract, click the button labeled ?Start?
6) Then type the path to your WinME installation files where it says ?Restore From? (example: D:\Win9x)
7) Type in ?C:\Windows? where it says ?Save File In? and click OK.
8. Naturally, back up your registry and move a copy of the deleted keys to your desktop before removing them.
9) Delete HKEY_LOCAL_MACHINE,System, CurrentControlSet, Services, ICSharing (the whole thing).
10) Delete HKLM\System\CurrentControlSet\Services\ICSharing (entire folder)
11) Delete HKLM\System\CCS\Services\RemoteAccess\LocalNameResolution (all keys)
12) Extract ics.inf, icshare.inf and icsharep.inf to a temp folder (like C:\ICS) using steps 3-7 above.
TIP #20: Netconn.exe is still causing a crash.
1) Click Start/Settings/Control Panel/Add-Remove Programs/Windows Setup ? remove ICS. Do not reboot.
2) Click Start, click Run, type Regedit (hit enter)
3) HKEY_LOCAL_MACHINE,System,CurrentControlSet,Services -- Remove ICSharing key
4) Under Class, note the number of folders under the NETTRANS key. Don?t close, just go to the next step.
5) Under Network properties, add the protocol called NETBEUI and remove all instances of TCP/IP
6) Click OK. DO NOT reboot.
7) Back to Regedit, press F5 to refresh the screen.
8. Remove all folders under the NETTRANS key that WERE there before. Do not remove the new keys. They might be at the end, or in the middle. Don?t remove the new NETBEUI folders.
9) Back in Network properties, add the TCP/IP protocol.
10) Be sure that File and Printer Sharing is not present (this is a must), and delete the NETBEUI protocols.
11) Click Start/Settings/Control Panel/Add-Remove Programs/Windows Setup ? Communications ? select ICS. Click OK, Click OK.
12) ICS should run perfectly.
13) At this point, at your discretion, you may open network properties and add File and Printer sharing.