Hi kt. Sounds as if you'll need to change it to a .jpg or something in common use, then use some sort of graphics editor to resize. If you don't have one, download Irfanview, free, and after setting it up to accept all file types, just load your pic, and 'Save As' **** .jpg. From there you can resize, resample or whatever you want, within reason. This is a guess because I don't know your original format.
Geoff.