What may cause it? You have to be clear in the answer. Who handles the LAN at your work, or is this a place like a Boy's & Girl's club, that there is not one specific person. If it is you, I would suggest getting the appropriate book on Windows AD. Microsoft Technet has a lot of good info online. You can also go to slipstick.com for info.Yes sir, what do you think it may cause that?