Keyboard miss behaving

Afternoon, I have a aspire E1-531 which i bought to replace my old Toshiba to finish my last year of uni and i seem to of had nothing but problems. randomly in middle of sessions i can be typing and then all of a sudden my keys instead of typing are performing other functions like opening up files, image gallery search box and i have no idea how to fix this and end up just switching off and leaving it for a few days on which sometimes this issue is still in presence, can anyone help please. Thank you