Is there a limit to the number of allowed characters for Windows computer names? If so, what is the limit?

  • I've heard it will handle over 9,000 before you start to see issues.
    – Josh K
    Mar 16, 2010 at 20:42
  • The text field in the dialog for changing the name on XP seems to have a 64 character limit.
    – FogleBird
    Mar 16, 2010 at 20:53
  • The other issue you could run into is UNC paths. There is a max length for UNC paths (256 characters???) so if your machine name is long, and you have long share names, or deep directory structures, you could have issues.
    – BillN
    Mar 16, 2010 at 23:13
  • The input field in Windows 10 let you enter a much longer name then 15 characters, but responds with "too long computer name". The question is: Which number between 15 and 63 is actually valid?
    – PeterCo
    May 19, 2016 at 10:19

1 Answer 1


According to MS KB, maximum length varies based on the name resolution protocol.

NetBIOS computer names:
Minimum name length
1 character.

Maximum name length
15 characters.

DNS computer names:
Minimum name length
2 characters.

Maximum name length
63 characters.

  • 3
    Microsoft also notes this in the same article: Note Windows does not permit computer names that exceed 15 characters, and you cannot specify a DNS host name that differs from the NETBIOS host name. You might however create host headers for a web site hosted on a computer and that is then subject to this recommendation.
    – Jack
    Nov 6, 2015 at 20:43
  • 1
    This seems to have changed. I just set up Windows Server 2019 and it would allow me to enter a name with a length greater than 15, but it does warn that the hostname will then differ from the NetBIOS name. I'm not going to risk that complication, but it seems like I'd be allowed to. Feb 27, 2019 at 17:03

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