If you don't know and don't care what Grid Granularity is, this tool isn't for you. Comprehensive System Information offers numerous details for nearly every facet of your computer, but it's not aimed at the casual user.
The interface is simply designed, with a tree list from which to choose a category and a large display on the right that shows selected data. The five main categories are Hardware, Operating System, Installed Applications, WMI Service Management, and Performance Counters. Newer users will probably stop after checking out just one of the lengthy submenus. You have to know where to go to find what you're looking for. Users expecting to see the friendlier icons of Add/Remove Programs will be disappointed...and probably confused to see, instead, Check Checks, Command Line Access, and nearly a hundred other options. You can print or export values, or copy the data to the clipboard.
System admins will jump right in here, but this isn't a tool that will benefit less experienced users. The 30-day trial version has no limitations, and it's certainly long enough to see if Comprehensive System Information suits your needs.