This is the Lego Creator Harry Potter fix write up

This game can still be installed via the disc today, however you must do some small extra bits to be able to install it correctly. On the Setup.exe file before you run the installer you will want to right click it, properties, compatibility and click 'run this program in compatibility mode for' and set the drop down to 'Windows 98 / Windows Me'. Then also tick the 'run this program as an administrator' option. Once done click Apply and OK.

You will also need to download and install this program (Double Agent). This is not only required to properly install the game but also to be able to play it, as if booting up without it then the game will just crash after creating a profile. This program is what was used for the Lego man who talks to the player during the game, which the software for this was dumped by Microsoft after Windows XP.

Once you have done all the above you should be able to play Lego Creator Harry Potter with no issues. As it currently stands there is no was to improve the Resolution or Aspect Ratio of the game so you will have to play it with the default which is (800x600).