Number keys do strange things

ptf Posts 1 Registration date Tuesday October 27, 2015 Status Member Last seen October 27, 2015 - Oct 27, 2015 at 02:59 AM
Suddenly when I press any number from the number keys row (below the Function keys) the system do a different action, working with Microsoft Excel or Word, any number opens automatically the "Save as" window, working in Google it opens a right side windows showing the HTML 2code of the page, etc.
I guess I activated some behaviour pressing a combination of keys but I don't know how to check it and I need to know how to deactivate it
Can anybody help me with this problem?