
There are times that the pre-installed Microsoft Paint comes in handy when you require to do a simple image/photo editing urgently. However, sometimes you might need some extra tools/functions to add more impressive effects to the photos, Microsoft Paint is not allow you to do so. Even though the latest Microsoft Paint in Windows 7 uses Ribbon UI just like in Microsoft Office 2007 and some extra features such as neutral brushes, it still can’t be used for complex photo editing task, eg. layering as in Adobe Photoshop.
Paint.NET
Paint.NET is the only free photo editing software that supports layers just like in Adobe Photoshop. Layering is very important as it can helps to cancel anything that you have made on the photo by just deleting the layer which consists the changes. If you wanted to know more, head to here. Other than that, paint.NET does support plugins and have a lot more features, but the most important one is that it has an active and growing online community which is very important for a software.
It started development as an undergraduate college senior design project mentored by Microsoft, and is currently being maintained by some of the alumni that originally worked on it. Originally intended as a free replacement for the Microsoft Paint software that comes with Windows, it has grown into a powerful yet simple image and photo editor tool. It has been compared to other digital photo editing software packages such as Adobe® Photoshop®, Corel®Paint Shop Pro®, Microsoft Photo Editor, and The GIMP.
Features
Have a glance through for their features in paint.NET here. I personally love their special effects and unlimited undo history the most!
Screenshots
Check out the screenshot below, it shows you the interface of paint.NET which is quite impressive for a free software.

For more screenshots, you can head to here to check them out.
System Requirements
Minimum System
-
Windows 7 (recommended),
or Windows XP SP2,
or Windows Vista,
or Windows Server (2003 SP1 or newer) -
.NET Framework 3.5 SP1 (free download from Microsoft)
-
512 MB of RAM
-
1024 x 768 screen resolution
-
200+ MB hard drive space
-
Optional: 64-bit mode requires a 64-bit CPU and a 64-bit edition of Windows
Please note that Paint.NET uses your hard drive to store temporary files related to undo/redo history. Because of this, actual disk space requirements will depend on the type of actions you perform on an image, and on the size of the image.
Download
You can download the software from their official site which can be accessed here.
Paint.net is a great software, definitely!