Online game guide
The Wiki is an online knowledgebase and is also free. So it’s not very likely that you purchased and downloaded it. Who did you purchase the guide from? You’ll probably need to get help from them, if something isn’t working right.
Odds are, if you downloaded a file, it’s a PDF document. If so, then you’ll need the Adobe Reader (or other utility that can read PDF files). Then you need to find the file you downloaded and open it up with that reader.
I purchased it at the same time I bot GW2 online. It was an extra you could get. I thot I was buying the hardcopy, which is what I wanted, but it turned out to be an online copy. Thank you for your input.