Microsoft has told IEAK (IE Administration Kit) partners to freeze distribution of builds of IE5, following the discovery of a "serious problem" that stops Win2k users logging on to their machines. The gotcha relates to the installation of the 128-bit security patch for IE 5.0, 5.0a and 5.0b on Win2k as part of an IE5 IEAK package, and is caused by "important security files" in a Win2k installation being overwritten by older ones. Older files already, and it's just started shipping. But the problem doesn't affect Win95 or Win98. The files get overwritten Win2k on installations created (according to instructions) using the command line switches "/q:a /r:n /n:v", with the /n:v switch being the problem. Users get the message "System cannot log you on because the domain Computername [i.e. Your domain name] is not available, and the culprit overwritten files are saenh.dll and schannel.dll. According to a warning sent out by Microsoft yesterday: "It is critical that you freeze distribution of IE 5.0, 5.0a or 5.0b builds that incorporate the 128-bit security patch with these switches. Please take immediate action to help prevent more customers from encountering this issue." ®