On a PC of one of my friends, we have a problem with MSN Messenger. Since a while, we cannot connect anymore. When trying to sign in, we get the error:

"Signing in to .NET Messenger service failed because the service could not be found"

We have tried various possibilities to resolve the issue such as found everywhere on the net. We have the latest MSN Messenger version. It has just been installed. The latest Windows patches are installed. We have Windows '98. Anyone knows what could be a workaround to resolve the issue?