Loss of profile of user in NT4

All personal settings for the programs I use are lost when I log on as user.
All returned to the default values…
As Administrator I still have my settings as if nothing happened.
To access the LAN I have to log on as a user.
Before taking drastic steps I like to know if someone else had similar problems or have an idea on what to do.
I have Admin rights and use Win NT 4 with SP6
Thanks Folks