Trouble Updating Software

Trying to download new iTunes but keep getting the following error: (NSURLErrorDomain error -1012.)(-1012).

What is the problem and how can I fix it?

I am running OS X 10.8.5 (12F2542).

Previously, ever time I updated the operating system, I had ended up having to reinstall it as it would lose needed information needed to log into the App Store and iTunes Store.

Any ideas?