Performance of a Windows PC depends on various parameters: its hardware specifications, running processes, startup items, installed software etc. So, to troubleshoot any issue, you need to know such details. PC HelpSoft Smart System Informer is a tiny freeware that provides all such information. According to the webpage,
Smart System Informer is a free tool that compiles all the information you need on installed hardware and software. Specific information includes computer ID, processor, BIOS, memory, disks, video, motherboard, monitor, etc. This information shown as number and graphical views - you can easily evaluate your computer's performance, and save the received data as a text file.