It seems I remember you having trouble opening the files from my site a while back. I have no idea why you can't open the PDF files. Every computer today has a PDF Reader software on it and should be able to open the files. I have checked on multiple computers and the files open just fine. I really don't know what to tell you.
All you need to do is click on the PDF file links on my TABs page and the file should open up in your Acrobat Reader. If not then right click and save as to your hard drive. The PDF and MIDI files should open for you no problem. If you want to work with the Powertab files then you have to download and install the Powertab program and there is a link at the top above the table of tabs.