After opening Eclipse once and without updating, it does not open again. It spits out the error "The Eclipse executable launcher was unable to locate its companion shared library." and does not open. I have Windows and used 7-Zip to unzip the file (I have read that windows default unzip tool corrupts the file). I would like to emphasize that it works once and without updating, but then if closed, will not open again. Thanks for any answers.
That's a very weird behavior.
The Eclipse executable launcher was unable to locate its companion shared library error popup does indeed happen when you don't expand the archive according to Windows' bizarre requirements, and it seems you've documented yourself well enough before posting this.
I would advise: