I am terrifically inexperienced with running a network. The error mentioned in the title occurred today out of the blue. When I came in this morning I was able to log in fine. When I left for about 3 hours and came back to find my computer locked as usual I attempted to log back in. Instead of logging in I got the aforementioned security database error. I read through other articles on the matter but they talk of forests and such which means nothing to me due to my inexperience. The server is in our office, my workstation is separated from the server by only a switch. The server is running Windows Server 2008, my workstation is running Windows 7 professional. Can anyone please offer a lamen's explanation of what I should do here? Thanks in advance for anyone's consideration on the matter!