How to Resize a wallpaper in Windows Paint Tutorial:
To resize a wallpaper in MS Paint, follow these simple steps:
1. Open Start > All Program > Accessories > Paint
2. Drag your image into Paint or Menu > Open > Select Image
3. Find Resize on Home tab and click on it
4. You will now see the Resize and Skew box. To modify picture size click Pixels. Insert pixel value in either Horizontal or Vertical box and you will see the other value changes automatically. Don’t forget to tick Maintain aspect ratio or otherwise your image will be stretched.