I am not familiar with the technical term “washed out my screen.” Can you elaborate, please ?
You can look at the scripts with a text editor. There is no command causing a reboot.
(But I have heard in the Microsoft forums of Win 8.x getting caught in restart loops for other reasons.)
Fist of all, it checks SketchUp registry settings, (in the current user hive,) so the install must have been properly finished (and the installer should have been run via right-click “Run as administrator”.)
If you had uninstalled SketchUp prior to trying to read the registry settings, then there would be nothing to read. (And then error messages from reg.exe would indeed output that message.)
If SketchUp was still installed,… then it sounds like you do not have Administrative privileges, or did not run the cmd scripts via right-click “Run as administrator”. They can also be run by running a cmd shell via the right-click “Run as administrator”, and manually calling the cmd script. (But I’m not going give you shell command lessons here. It is not the place.)