Fix for 'The server name is invalid' error when installing Exchange 2007 Management Tools

Friday, November 6, 2009

You may receive the following error when installing the Exchange 2007 management tools on a computer:

The server name is invalid. It contains characters other than 'A'-'Z', 'a'-'z', '0'-'9' and "-".

While the error indicates that the problem is with the server, it's actually with the name of the local computer where the Exchange 2007 management tools are being installed. The most common reason for this I've seen is when there's a underscore "_" in the local computer name.

The fix for this is to replace the exbpa.prereqs.xml file on the Exchange Server 2007 installation source with the RTM version of the file.  Here are the steps to do this:
  • Download the RTM version of exbpa.prereqs.xml from this blog (right-click the link and choose Save target as...) and save it to a temporary location
  • Disable automatic updating for Exchange 2007 setup. Otherwise, setup will automatically download the most recent version of the file and replace it. Run the following command at the CMD prompt:
reg add "HKCU\Software\Microsoft\Exchange\ExBPA" /v "VersionCheckAlways" /t REG_DWORD /d 0 /f
  • Copy the exbpa.prereqs.xml file you downloaded earlier to the \setup\serverroles\common\en folder on your Exchange 2007 installation media.
  • Now run setup and install the Management Tools, as usual.  You will still see the same error message, as shown above, but you will see an Install button instead of a Retry button.
When the installation is complete, remove the VersionCheckAlways registry key to reenable the automatic update feature using the following command:

reg delete "HKCU\Software\Microsoft\Exchange\ExBPA" /v "VersionCheckAlways" /f
Keep in mind that you may have to do this same procedure again in future update rollups and/or service pack updates.


  1. Hi, thanks for the guide, unfortunatelly, it does not work for me, exchange installation says, that exbpa.prereqs.xml has been modified :(

    Unfortunatelly, I have BackupExec media server on this server, thats way I need install Exchange Management Tools on this server - name is with underscore :(

    thanks for any help

  2. I just checked the exbpa.prereqs.xml file and it looks like it became corrupt. Sorry about that. :(

    I've downloaded another version of the file. Please try it again and let me know that it works. Thanks.

  3. Hallo Jeff

    it works perfecty, thanks for help :)

    but, one little question, maybe it does not regard this problem. when I run management tools on the server, where I just installed them, error occurs: Active directory server is not available.... (its funny, because this is that DC server) :)

    thanks again, good luck


  4. It sounds like the user profile on your DC is corrupt. Log on to the DC with another account and delete the problem user profile from User Accounts in Control Panel. Then login and try again.

  5. Hi Jeff,

    Can you post an update regarding this same issue with Exchange 2010? I would like to install the Management Tools on a PC with an underscore in the name.



  6. Hi Jarrod,

    I just confirmed that this problem does indeed affect Exchange 2010, too. Unfortunately the workaround above will not work for Exchange 2010 since the XML files are entirely different. I'll see if I can come up with a solution, but it may not be possible.

  7. Hello Jeff, nice solution, but not working on 2010. Have you found any solution?

  8. No, there is no solution for 2010. :(

  9. Thanks so much for this!

    Microsoft should really just release the PowerShell cmdlets for Exchange 2007 so we don't have to jump through all these hoops!

  10. Thanks, very helpful :)


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