Whether you want to know how much RAM you have on a machine or if some software or service is present on a PC, the msinfo32 command gets it to you fast. The Windows key + Pause/Break key is good too but provides only basic info.
To try msinfo32, go to Start > Run, type msinfo32, and then press Enter. That’ll give you in-depth info about the Hardware Resources, Components and Software Environment.
Belarc Advisor is a free tool that can audit a PC & find all installed software and hardware, including Microsoft Hotfixes