Windows offers a lot of sources of PC information, most of it scattered throughout your system. Gabriel Topala's SIW (System Information for Windows) gathers all that information in a single interface. SIW Technician's Version displays detailed specifications for your hardware, software, and network, including real-time monitoring of CPU, RAM, and network usage. It includes several useful extras, such as the ability to retrieve and display passwords and software serial numbers and key codes. Best of all, it's free for noncommercial users. It doesn't access or make any changes to your properties or settings; it just displays the most detailed system information imaginable in one central location.
One great thing about SIW, right off the bat: it's completely portable, requiring no installation to run, and it's only 1.53MB in size, so it fits on a wide range of portable devices. SIW will run not only from USB flash drives and other portable devices but also from a network drive or domain log-in script. It has a familiar Windows-style interface, with taskbar, left-hand explorer panel, and main view. What at first seems a dizzying array of information in the navigation panel is in fact a well-organized layout, with expandable views for Software, Hardware, and Network, each with related items grouped by function; for example, under Hardware are entries for Devices, Video, and Ports as well as System Summary, Motherboard, Printers, and other related items. There are even properties settings for Logical Disks and Battery. The file menu and taskbar each contain many useful settings and some extras, such as the Eureka password retrieval tool.
There's a coffee cup icon on the taskbar labeled Buy Me a Coffee that links to the developer's PayPal page; SIW is Portable Freeware, but tips are accepted. Even then, SIW is one of the best bargains in software, and highly recommended.