You should never try and remove the watermark from any print or screen capture.
It also includes a screen capture function and an interesting paper print ability which generates files that you can print if you are in need of paper with lines, graphs or blank musical staffs printed on it.
Make a screen capture of your desktop background on the computer and place all of the icons in a folder.
Then, set the screen capture as the new desktop.
One of the ways that you can get whatever character sprite you'd like is to download an emulator, get your hands on the video game ROM you want, and then simply do a screen capture on your computer.