There are certain files and folders (like the hosts file in Windows System32 folder) that you can only open /edit if you are logged in as the administrator of that computer.
This quick video tips explains why disk defragmentation is essentials and how you can quickly defragment your computer’s hard drive.
This article describes how you can quickly minimize all open Windows except the active one. Screencast video included.
The webmaster team at Google has put together this 20 minute video presentation with tips on how to improve your site’s presence on Google and how to deal with common issues like duplicate content, fluctuating PageRank, image search, etc.