Adobe Reader X should still work but it is out-of-date because it was replaced in October 2012 by version No. X1.
It might be worth re-placing your present edition with Adobe Reader X1.
It is also possible that a 'nastie' has got into your laptop and it needs to be flushed out with Malwarebytes. If you haven't got Malwarebytes then I suggest you download the free edition (refuse any trial of the paid-for version) and see what a quick scan reveals.:-
http://www.malwarebytes.org/
Hans.