Can't get SQL Plus to open

I installed SQL Plus on my Windows 11 machine on Friday. And I was able to start it up and work in SQLPlus. Now it is two days later, I go into the Windows Start menu, find SQL Plus, click open, nothing; click open as administrator, nothing; go into file explorer, try to open the program from there, nothing. SQLPlus is on my machine, although it doesn't show up in services, but I can't open it up and run it. Any advise would be appreciated.