Quicktime Pro any good?

[aznever]

I'm thinking of purchasing Quicktime Pro for Windows XP platform.
Can anyone give me their opinion or views relating to Quicktime Pro. I am very much a beginner in Video editing and need to start learning fast about video compression to send via internet or upload to web pages.
At presetm I edit video in Stidio 9 and choose the video compression facility within this programme but it is not enough. The clips continue to be too large!