Does Paint.NET support 64-bit processors?
Yes. Since v2.6, Paint.NET has had support for 64-bit mode if both your processor and operating system support it. For example, if you have an Athlon 64 processor and are using Windows XP Professional x64 Edition, you will get the benefit of faster performance and the ability to work with larger images. There isn’t a separate installer for 64-bit Paint.NET. It is detected and used automatically.