Welcome to Natron!
Windows 7 is not supported, but @rodlie did a fix for Natron 2.3.15 which you can find here: To bug or not to bug ^^ - #17 by rodlie
I don’t know if that fix still works for 2.4.0.
You probably know that Windows 7 is not supported anymore by Microsoft since Jan 24, 2020. If you have a way to upgrade to Windows 10, it is highly recommended. It seems like you can still have it for free: https://www.cnet.com/how-to/how-to-download-windows-10-for-free-now-that-windows-7-is-dead/