Do you have Photoshop?
If you have it, just make new transparent picture. Then click Ctrl + Shift + Alt + S and save it in Png-24 format. Then go here: Dynamic Drive- FavIcon Generator and upload your icon and website will transform it to .ico format
If you want to transform it to normal icon (not to favicon), go here: ConvertICO.com - Convert .PNG format files to .ICO or .ICO format files to .PNG : Windows Vista compatible icons
Hope i helped you (thanks + rep me)