Help please

Hi Hive mind. Please help. My Photoshop has gone weird. If i am in the program, i can open files from the program no issue. But i cannot open any files in with photoshop from outwith the program. Make sense ? If i click on any file it will ask ( as normal ) what program i want to use to open file. In that menu, photoshop only shows as photoshop.exe. I click on that and nothing. If i look for the option of find another program on this pc, i can find photoshop but again i only have photoshop.exe. Have uninstalled and reinstalled multiple times but still exactly the same. Have tried redoing the default app to open files option but nothing. Any ideas please ? Thanks in advance