The minimum system requirements needed to run Paint.NET are as follows:
Windows 7 (recommended) or Windows XP
.NET Framework 3.5 SP1
A 800 MHz processor
512 MB of RAM
More than 200 MB of hard drive space
A 64-bit CPU and a 64-bit edition of Windows for 64-bit support (this is optional)
A 1024 x 768 screen resolution
At present, there is no Mac version of this product.