You’ve scanned in a job lot of photos and discovered that a handful are slightly skewed – no more than a couple of degrees, but it’s amazing how such a small mistake is magnified when you view the photos on your computer.

Quick and easy straightening tools are provided by the likes of Windows Live Photo Gallery (part of Windows Live Essentials), Google Picasa, and Adobe Photoshop Elements, but you don’t need to spend a penny or install a photo cataloguing tool in order to fix the problem. Read on for our guide to straightening old photos yourself with the help of the superb – and free – Paint.NET tool.

Open your image in Paint.NET and choose File > Save as and saving a copy of your original image in case something goes wrong. Once done, choose Layers > Rotate / Zoom.

Now, either click and drag on the Roll/Rotate icon or enter a figure (a negative figure for anti-clockwise, positive for clockwise) into the Angle box – the picture will update immediately.

Click OK, then use the selection tool to select the portion of the straightened image you wish to keep. Choose Image > Crop to Selection to finish the process before saving your image.