I'm sorry to be pedantic but you don't print pictures from your computer, you print them from a program. Since you've not told us which program you're using (and there are hundreds, if not thousands, of possible programs) it's hard to help directly.
In the absence of any information about which program you're using, I'll try to provide advice based upon a program that most people have, Microsoft Word. Yes, I know it's a word processing program but you can use it for printing photos. Here's what to do:
Open a blank document.
Go to Insert>Picture>From File.
Navigate to the location of your image and double-click on it.
In the Word document, right-click on your picture and select Format Picture.
Click the 'Size' tab
Adjust the dimensions to those required for printing. and click OK.
Click on File>Print and then on 'Properties'
Adjust your printer's settings to optimise it for photo output.
Click OK twice.
Chris



