If you have multiple results returned, click on the one you’d like to view. If there is only one result, your PC will automatically try to download and open the document as a PDF file to view it. Depending on your default browser this may be handled differently. In Internet Explorer, a popup window will ask you if you want to open or save the document.
In Chrome, if the document does not open when you double click it, it may have been blocked by the Pop-Up Blocker, as shown here. You will need to right click on the icon and choose to open the document, or trust pop-ups from this site. You can then choose to save the document and open it.