I got a call from an associate on how to change a domains NetBIOS name from lower to upper case. At first I was stumped, Was I the one that was out of date. In my head an NetBIOS name is always in uppercase, the same as a FQDN is always in lowercase. Don’t get me started on the special case with Single Label Domains (SLD). First I turned to my colleague Jimmy Andersson to ask if I had missed that day in AD training on why one would do that, he could not really give me any good reason or how. So I turned back to associate that reported it from the beginning. It was a regular Windows 2012R2 installation that had done this. So I tried with a Windows 2012R2 Update installation. And low and behold.. I managed to get the NetBIOS name in lowercase.

A small powershell script to verify NetBIOS name:

Get-ADObject -Searchbase "CN=Partitions,$((Get-ADRootDSE).configurationNamingContext)" -Filter {objectclass -eq 'crossref'} -Properties nETBIOSName,dnsRoot|?{$_.nETBIOSName -ne $Null}|select nETBIOSName, dnsRoot

How to do it:

The problem is that its easy to do this error. If you don’t remember to hold shift while typing the NetBIOS name you will get a lowercase NetBIOS name.

Windows 2008R2:

Windows 2012/2012R2:

Windows 10 Technical Preview 2:

So after Windows 2008R2 be more careful when creating domains, Not all safe guards that were available in dcpromo has been ported to the server manager.