Thanks for your help, Shades, Dormouse, and Carol Haynes! I will download System Information for Windows (XP) now.
The only reason why I wanted to use XP is because I've heard that Vista was a resource-hog, and it seemed impossible for end-users to close the backdoors in Vista, which was developed by notorious homeland spy agencies, such as NSA. It bothers me, so I try to avoid their latest products.
I don't meet a lot of Vista-enthusiasts. Please share your opinion about those 2 operating systems with me.