We had this same error message but on a Linux server (RHEL6.2).
For the benefit of anyone comes across this post while searching the same error, the problem in our case was that the server (hpsum was being run locally and silently on a client server) had too many IP addresses bound and for some reason that was causing issues with SOAP server login. Once we turned off all the dummy adapters temporarily the process worked fine.
Took me quite a while to troubleshoot hence posting here in case it saves anyone time.