I was about to recommend Serif’s Photoplus 5 as an excellent freeware digital imaging program, quite similar to PaintShop; but we just found that it’s rather resources-intensive. The Photoplus application shows almost 100% CPU Usage — even after closing.
Perhaps one could try downloading Adobe’s free Photoshop 6 tryout. Though the product description says one may not save or export from the tryout version, it says nothing about composing in Photoshop and doing a flattened screen capture to open in another graphics app… ;)