The easiest way is to Print screen, (the Print Screen button on your keyboard).

With the Task Manager open, hold down the ALT key, then press Print Screen and this will copy the Task Manager only window as an image to yor clipboard.

Then open up Paint, (Start > All Programs > Accessories), or your favorite image editor, goto Edit, the click Paste, and the image will be copied to the Paint program. From there you can save it, or print it out as an image, (not as text).

I hope this helps.