Here, download the GIMP (
http://gimp-win.sourceforge.net/) for all your image editing needs.
To resize an image, right click to open the toolbar, and then got to
Image -> Scale Image
Then just input the width or height. You only need to insert one: the other will automatically re-adjust so the image doesn't stretch out of control.
Oh, and dude: please only one sig image, eh? ;)