My quest similar to Avel in that I want an equally high quality image of 8x10 inch from a wallpaper I downloaded from the web of 4x3inch and resolution 72

Have you tried a more indepth search for a higher quality image ?

When working with digital images, if you have a lower resolution that you want to make bigger, the result will be very poor quality. It is best to go from high to low resolution, preserving the pixel information. Ben is correct, you will need to find a similar image at a higher resolution. If you are trying to print it, you will need something like 2400x3000 pixels at 300dpi.

Fotolia.com or istockphoto.com are very inexpensive alternatives.