Paint.NET is a free graphic editing program.
Latest version is 3.22

Minimum system requirements :

• Windows XP (SP2 or later) / Vista / Server 2003 (SP1 or later)
  
  
• .NET Framework 2.0
  
  
• 500 MHz processor (Recommended: 800 MHz or faster)
  
  
• 256 MB of RAM (Recommended: 512 MB or more)
  
  
• 1024 x 768 screen resolution

Download :

> Download paint.net (Size : 1.6 MB)

what's this program ? Paint.NET

It's an image / graphic editor.

Good features and light on resource usage.
A cross between MS Paint and Photoshop.