Some documents are in .pdf format, and to read these, you need Adobe Reader.

On trying to open the documents, if you are using Internet Explorer, you may possibly get a message on the bar at the top of the screen that says

"To help protect your security, Internet Explorer has restricted this file from showing active content that could access your computer. Click here for options…."

This is not a fault, and is normal, depending on your security settings, but please read the options, and satisfy yourself regarding security before proceeding if you are in any doubt.