In this tutorial, I will show you how to add a border to a picture using the free program Paint.NET.
Here is the picture I will be using.

Step One
Open up your picture (Ctrl + O).

Step Two
In the lower left corner, you will see the color palette. Click on it to make it the active window.

Step Three
Switch from the Primary to the Secondary by using the drop down box. Then, pick a color. The secondary color is the color your border will be.

Step Four
Go to Image --> Canvas Size (Ctrl + Shift + R).

Step Five
The Canvas Size dialog box will come up.

In order to add a border without changing the pictures dimensions when complete, you will need to check the "By percentage" option. You can see in the middle of the dialog box the pictures current dimensions; in this case, 800x600. At the bottom, make sure the anchor is set to "Middle." You can change this by using the drop down box or clicking in the middle box.
Go ahead and reduce the dimensions by 1% (for a total of 99%). You will see the dimensions change in the middle.
Click OK.
Step Six
Here is the picture reduced by 1%. Now we are going to add the border and bring the picture back to the original dimensions.

Step Seven
Go to Image --> Canvas Size (Ctrl + Shift + R). This time around, you are going to increase the dimensions by 1% (for a total of 101%). Make sure the anchor is in the middle.

Click OK.
Step Eight
Viola! Here is the picture with a border that is approximately 8x6 pixels (1% of the original picture size), but notice that the picture is also back to the original size now!

Step Nine
Go to File --> Save As... (Shift + Ctrl + S).
Remember: Make sure when you go to save the file, use the "Save As..." option to rename your picture. This will prevent you from saving over your original copy of the picture. If you do, there is no fixing it. Here's a tip: When I edit a picture, I like to copy the original and edit the copy so if something like that does happen, I did not ruin the original picture!

Written by Tyler Clegg (roushtage2) for Meguiar's Online Forums. If you find any errors, please let me know so that I can get them fixed! Thanks!
Here is the picture I will be using.

Step One
Open up your picture (Ctrl + O).
Step Two
In the lower left corner, you will see the color palette. Click on it to make it the active window.
Step Three
Switch from the Primary to the Secondary by using the drop down box. Then, pick a color. The secondary color is the color your border will be.
Step Four
Go to Image --> Canvas Size (Ctrl + Shift + R).
Step Five
The Canvas Size dialog box will come up.
In order to add a border without changing the pictures dimensions when complete, you will need to check the "By percentage" option. You can see in the middle of the dialog box the pictures current dimensions; in this case, 800x600. At the bottom, make sure the anchor is set to "Middle." You can change this by using the drop down box or clicking in the middle box.
Go ahead and reduce the dimensions by 1% (for a total of 99%). You will see the dimensions change in the middle.
Click OK.
Step Six
Here is the picture reduced by 1%. Now we are going to add the border and bring the picture back to the original dimensions.
Step Seven
Go to Image --> Canvas Size (Ctrl + Shift + R). This time around, you are going to increase the dimensions by 1% (for a total of 101%). Make sure the anchor is in the middle.
Click OK.
Step Eight
Viola! Here is the picture with a border that is approximately 8x6 pixels (1% of the original picture size), but notice that the picture is also back to the original size now!
Step Nine
Go to File --> Save As... (Shift + Ctrl + S).
Remember: Make sure when you go to save the file, use the "Save As..." option to rename your picture. This will prevent you from saving over your original copy of the picture. If you do, there is no fixing it. Here's a tip: When I edit a picture, I like to copy the original and edit the copy so if something like that does happen, I did not ruin the original picture!

Written by Tyler Clegg (roushtage2) for Meguiar's Online Forums. If you find any errors, please let me know so that I can get them fixed! Thanks!