Using Spring lobby as spring downloader?

[gatecrasher48]

Hey all, I'm pretty new to spring and I'm sorry that this question will be so basic, but...how on earth do you use spring lobby as the spring downloader? I've had luck downloading maps from such sites as http://www.ta-spring.com/maps/ but as far as trying to search for missions or whatnot, I have no luck. How is this done? I've tried opening up spring downloader directly but with my operating system (vista 32 bit home edition) the lone downloader will not open at all. What is going on?