Max out RAM with number display

Well here's my new blog, basically I'm just going to be posting what I'm doing in programming. I'm currently learning C# using Microsoft's Visual C# Express. This is a program I made using a StringBuilder. Basically it rapidly lists every number from 0 to 30,000,000. It takes my RAM usage up from 23% to 59%. If I go any higher of a max number it goes up to 75% then crashes the program. I noticed some programs are running a little slow especially Paint, though Internet Explorer is still near full speed. This is normal using 59% of 3GB RAM. This program runs for approximately 8 minutes before reaching the final number.