It looks like he used MyPal, a Gecko-based browser. I usually use Supermium, which is chromium based and updated more frequently.
I'm currently browsing on a Windows 7 Ultimate computer. It was built in 2006 and has 12GB of DDR3 RAM, a 2TB mechanical and a 256 GB solid state drive, a blu-ray drive (which I added), an Nvidia Quadro K4200 GPU (a fairly powerful unit), and a 64-bit 4-core 8-thread Intel Xeon CPU. Yeah, quite the beast back in the day. And I bought it for $20 last year.
As for security risks, most antivirus programs still run on Windows 7, and there are even some that will still run on XP.