Four Laptops Not Working Properly, One Very Old

Hi! I have three laptops at my mother's house right now that I want to try to get to work. One is a Win7/32 one, and, even though the person who gave it to me said it had no password, I couldn't log on. A few hours ago I downloaded and used a program to reset the password, it confirmed the computer had no password. I think maybe I am using the wrong user account. I asked about that and am waiting for a reply. The other three laptops all are missing the power supply. BTW, I just remembered that somebody here mentioned a universal power supply, but I want at least two to be on at a time, along with other computers. I'll try amazon.com now.

 

Uhh...how do I find which cable I need? The site says "universal" but gives me model information and watt specifications.