Please run the DesignSpark Electrical installer (EXE) as an administrator first.
If the installer still hangs, open Windows Task Manager (CTRL + ALT +DELETE on keyboard).
In task manager, check if you have duplicate 'designparkelectrical setup' or 'install_DesignSparkElectrical.exe' sub-task under 'install_DesignSparkElectrical.exe'.
In that case, right-click and end the task.
Then, look for the DesignSpark Electrical launcher in Windows search or the icon may already be present on your desktop. Double click and open the software, it should work fine.