If you don't have photoshop, and don't feel like 1) downloading the demo, 2) downloading a crack of the real thing (check the Media Trading Center), 3) paying lots of money for a legal version of the real thing...
The Gimp http://www.gimp.org/ is a (legally) free graphics program with lots more capability than MSPaint, and sharing many similarities to Photoshop.
I say this, because that sig is TERRIBLE. I'm sorry, but there's not a single aspect of it that I like.
Hmmm....try to do a style like this or something maybe? For one I suggest that u find big pics and resize them to ur liking and not stretching them if ur gonna do things in MS Paint >>; Even my first one looked better than the one u did lol I'm srry. But put more thought into ur work next time ya? Cause u know one thing...ppl will not hold back on here to tell u how terrible it looks
theres really nothin to say but get Photoshop and maybe Illustrator. For sure, dont even mess with anything else unless u want to use 3d then get maya or max or w/e. But you just need PS. its a staple in life
sorry to say it but that is bad....it looks like you just took a pic and resized it...but I can understand why its bad, because you said you used microsoft word/paint and its you first sig
here I'll help you out....click HERE(Corel Paint Shop Pro Photo trial)
and click HERE(for PhotoShop trial)