From the screen shot of your install log it appears you received a 1603 error. Please try the steps listed in Error 1603 | Install | CS5 products - http://helpx.adobe.com/creative-suite/kb/error-1603-install-cs5-products.html.
You may also want to review your install logs in greater detail by following the steps listed at Troubleshoot with install logs | CS5, CS5.5, CS6 - http://helpx.adobe.com/creative-suite/kb/troubleshoot-install-logs-cs5-cs5.html.
Finally your initial issue sounds more like an issue with the site you were trying to download the PDF from. Instead of offering you a PDF they offered you an ASPX file. I would try a different web browser once you have Acrobat reinstalled. It is either an issue with the site or your web browser. Try a different web browser if the problem continues.
Many thanks in responding to me.
I am not technically savvy and failed to follow your steps; I finally sought for help from customer hotline.
The problem is fixed with one little step missed: changing the system locale.
Interestingly is that, the XPro has giving me lots of chances to reinstall, especially during my urgent & important moments