Okay, I could see on your screenshot (already deleted)
that you have not registered any file association with UltraEdit itself. But according to the problems there are file types or protocols nevertheless associated with UltraEdit, perhaps done with Windows Explorer directly or indirectly. Many Windows users click on button OK without knowing what they confirmed here with that button click.
I suggest you start Internet Explorer, open Tools - Internet Options - Programs
, check the option Internet Explorer should check to see whether it is the default browser
and close the dialog with button OK. Next exit Internet Explorer and restart it. Confirm that Internet Explorer registers itself now as default browser to restore Windows default settings. Open Tools - Internet Options - Programs
, uncheck the option Internet Explorer should check to see whether it is the default browser
, close the dialog with OK and exit IE.
As I could see on your screenshot (already deleted)
your preferred browser is Chrome. Therefore start now Chrome. Follow the instructions given at Make Google Chrome your default browser
to register Chrome now as application for file types *.htm, *.html, *.xht, *.xhtm, *.xhtml, ... and for the protocols ftp, http, etc. Now you should have no problem anymore.
In case there are still problems, perhaps because you have uninstalled Chrome, but Chrome has not restored the file associations correct, see How do I remove Google Chrome from being my default browser?
If nothing helps, it would be necessary to use Process Monitor
to log which registry keys / values and which files are accessed resulting in the wrong behavior and therefore get the information what to change in registry to get correct behavior back.
You need administrator privileges to change any file association. You can temporarily disable UAC or run the applications "As Administrator" to make the necessary changes if you are using Windows Vista / Windows 7 with a default user account usually restricted.