You've downloaded a trial version of the full ('Pro') product, rather than the free version (which meets most people's needs anyway).
Assuming that you don't want to pay for the full version, uninstall Malwarebytes from your computer. Then, if you simply want the free version, download it from the relevant link here:
http://www.malwarebyt...cts/malwarebytes_free
You should note that the Pro version offers 'real time scanning' (which automatically checks the content of everything arriving at your PC) whereas the free version requires you to carry out periodic scans (or to simply wait until a problem arises).
Chris