Unwanted Context menu item

Open File Explorer, on the search bar, enter ''Master PDF''.

No results.

Skakner said:

I don't remember the source of the portable version

Have you tried to find the source?

dalchina said:

Hi, you might try the free Default programs editor (Google it) for convenience:

Here I have it open at my pdf extension.
If you select an entry, the Delete button becomes available.

I assume you've tried a registry search for e.g.
Master PDF Editor 5

O&O registry editor (free) (Google it) is more convenient for searching.

Excellent app. I have used it a lot in the past.
I deleted the item and it's gone for good now!

Problem solved!
I would like to thank each and everyone that spent time trying to help me!

EdTittel said:

Another option might have been Nir Sofer's excellent ShellExView, which shows Shell Extensions installed on Windows (in many cases, these drive context menu stuff) and lets users enable or disable them.
--Ed--

Actually I used the ShellExView but it didn't show something.