I don't know about security systems but unless it's the manufacturer's site you go to - there will often be a hidden catch...
Money - Adverts - Spyware - Malware - what you downloaded may have already given your computer a dose of something nasty - but don't panic.
Try to find where the downloaded file went to in your machine - if necessary download it again and make a note of where it gets sent to.
Look for the file - if it's kosher it may well have a pdf extension as in Filename.PDF. If so you will need Acrobat Reader (free download) to view it.
I hope it works out OK for you - others on here will certainly know better than me and I'm sure they'll help you if they can - be sure to answer any questions they may ask and to thank them. There is no need to thank me...
Good luck...
Peccavi
August 2013