Learning cypher and graph algos, but having desktop issues

I've been exploring Cypher and the Graph algorithms. It's been very interesting, but I do keep running into software issues. I tried to uninstall and reinstall neo4j, but the old install left behind breadcrumbs that broke the new install. I got it sort of working, but now neo4j desktop won't show up at all - it's a process, but the GUI never opens. How do I recover in that situation? I'm using the sandbox to get my project done (class project) but I'm going to have to recreate the project due to the 10-day limit on sandboxes, to do my demo. Where can we find good instructions on completely removing neo4j from a PC to get a good restart? I've tried google, but haven't found anything beyond "uninstall neo4j" - which didn't work.

That said, I find Cypher a really interesting language, and have been enjoying learning how the system works. It's very powerful, and rich with graph algorithms.
Thank you, Amelia.

Hello I've been in this situation too, but I looked at the registry error and realized that there was something about a .json file, luckily I saved a backup made by the same installer. then find the file, check the content, adjust the version, copy the file in the path that indicated the error and voila!
Check your error log

Saludos !!