Dear Lady/Sir,
Kindly I ask your attention.
Did you try another PDF file?
When it still doesn't open, I would suggest to reinstall the program and give it another try.
When not, try to install Foxit Reader and give it a try.
A lot of browsers have PDF viewer addons, so.......
Has the file extention association being set correctly?
You can do this at Configurations.
Hopefully I let you known enough, that you will find the answers you seek!
Good luck & have fun doing it!
Best Regards,
MeneerWitte
PS:
Merry Christmas & Best Wishes 2014!