I have enjoyed using the VPN Programme 'Anchorfree Expat Shield'( which provides a UK IP address)for some considerable time with no problem.S
Suddenly the programme will not launch and I get the Windows error message:-

'Open vpntray.exe has stopped working'

Windows then searches for a solution with no success and I am unable to resolve the problem

Try a system restore back a few days to when it last worked correctly.

Try uninstalling and then reinstalling the application, remember to record any settings you used.

Previously reinstalled without change.Could not restore system as all prvious restore points had disappeared.
Then found that other media player programmes were showing similar 'Stopped Working' messages and one which reported it had crashed on startup.
Reluctantly decided to reformat Windows!
Thanks to both.