is it possible to use the parallels win installation into fusion so i don't need to re-install all the stuff again?
You can. As Robin said you will find links on the Fusion forum, but be warned the converted VM will be single processor unless you do some fairly hairy registry edit. I have tried Fusion and given up on it. Unrecoverable errors when USB 2 connected. No-one on the forum or support able or willing to help. Other smaller problems on Fusion left me with impression that Parallels is better at the moment for me. Mike