Unable to find rasman.exe

Hi
Has anybody come across a problem like this before? In Windows NT 4.0 every time I try to dial up I receive an error message “Application error, unable to find rasman.exe” and then the machine hangs. This is the second computer I am having the problem on. With the first one, I uninstalled RAS and then tried to reinstall it, but it could not register the Modem, and also the Modem Properties in Control Panel became impossible to open. So I want to fix this one without uninstalling RAS, unless anybody can provide a fix for the second problem.

Regards