Gianluca Sartori helps Future Gianluca (and present us in the meantime) troubleshoot issues with xp_logininfo:
The user does not exist
This is very easy to check: does the user exist in Windows? Did you misspell the name?You can check this from a cmd window, issuing this command:
net user SomeUser /domainIf you spelled the user correctly, the command will return information about it, like description, password settings, group membership and so on.
There are a few other potential causes, so click through for those.