Wanted Freeware Raster to Vector Conversion

I am not that great at technical programs and cannot afford things like Corel... I am looking for freeware or shareware with full try before you buy capabilities that is not too exspensive to buy if I like it. I do digitized machine embroidery. Most of mine is hand punched..which means I do each part of the picture seperately until it is finished. I recently purchased DraWings to work with my digitizing program for auto digitizing:confused...but now I need something to convert the Raster files to vector files. specifically CMX and AI... is there such a product out there for this dummy? it must be easy to use. the raster files can be converted to stitchable files but they are all CROSS stitch and that I do not need. rolleyes I use XP Pro Media