cannot login to vault

hi all, bit in trouble here. we have the vault on a fileserver in our workgroup. has been working fine untill monday. i cansee the vault, i can read files from the folders etc. but we cannotlogin. tried so far, uninstall everything on file server, killregistry entry, reload with files from downloads. can seevaultdata, vaultadmin program starts, tell it which computer ( usename and 'localhost') it connects and then the list of users isempty. nothing i try will get me passed that. any thoughts please.
cheers mart
sw 2009 sp2SolidworksWorkgroup Pdm