Sorry to here you are having this issue, first let me ask… it sounds like we are talking about Chrome browser and not the os correct? If that is the case then sometimes you will see this white box as a pop up or redirection when something in windows has adware or malware trying to pop up on you . The easy fix Chrome suggest you try turning off the hardware acceleration in settings and system (second toggle). If that does not work then type in the white box chrome://settings/cleanup and hit enter. Chrome will run a cleanup tool and get you back where you want to be. Last you can go to chrome-more-settings-advanced-reset settings-restore. That will restore Chrome back to install.
Are you familiar with vmware? You can download a free (non-commercial) version of workstation at : https://www.vmware.com/products/workstation-player/workstation-player-evaluation.html So you are on your windows machine running vmware which creates a window and you can load chrome OS in the window. So your original windows is never effected, and if you have problems or just no longer need it you just close the chrome vm window. It will give you the opportunity to run many different operating systems in a vm-window and learn or test without ever damaging your main windows computer.
If you wanted to use that old notebook and turn it into a chrome book just follow these instructions and you will be amazed how good some of the old equipment can run as Chrome device. https://www.alphr.com/google/1003319/how-to-turn-your-old-laptop-into-a-chromebook-turn-your-sluggish-old-windows-laptop/2/