RRAS won't start (7024 and 20103)

I have a customer with two W2K SP4 UK Servers, which had
Routing and Remote Access running perfectly on it. Last week
he decided to do a windows update on both servers and reboot,
and RRAS now fails to start with the following errors:-

Event ID: 7024

The Routing and Remote Access service terminated with
service-specific error 2.

Event ID: 20103

Unable to load D:\WINNT\System32\iprtrmgr.dll.

I have followed article 299013 on the KB, but all is
fine. It also suggests reinstalling TCP/IP but I really
don't want to this as I'm not sure what may
happen!

Any ideas gratefully received

Ed