Unfortunately I don't know what to do. The error message seems pretty clear in that access to XMLHttpRequest is not being allowed. That is, it doesn't appear to be that there is an issue, such as something being corrupted or not installed correctly or anything like that, but rather that Windows simply isn't allowing access to XMLHttpRequest.
I found the Group Policy that controls this. When I disable it, the TD is unable to validate a license but it does not produce an error message. The software is simply unable to contact the server.
But who knows? Maybe it produces a different result on your system. On the Windows Start Menu, type "group policy", then click the "Edit Group Policy" item that opens. I'm currently using a PC connected to a domain controller, so this might not even show up on a personal PC. But if it does, open it. This should open a control panel window with "Local Computer Policy" at the top. Open the following:
Local Computer Policy -> Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Security Features -> AJAX
Then in the right-hand panel, double-click "Enable Native XMLHttpRequest Support". Mine is set to "Not configured", which I presume leaves it in its default state of "enabled". You might try explicitly setting it to "Enabled" and see if anything changes when you try to register the TD software. If that doesn't fix it, you might even try setting it to "Disabled" just to see what happens. It was my experience that this change took effect immediately without even the need to restart the TD, but you might want to just in case.
I honestly don't know what affect this will have, if any. I have no idea what is causing the issue for you, as I've never seen it before.
If you've purchased a license and are unable to register the software, I will of course refund it upon request. If we reach that point, please contact me via email: support@thetournamentdirector.net