Hi guys, i received parallels 4.0 as a gift 2 months ago and did not install the software. but now, as win7 is out, im really interested to get it installed, but is it recommended to run win 7 (64-bit) on Parallels 4.0 and not the latest version of Parallels? Sadly, i could not get it exchanged for parallels 5.0 in my local stores. Will it crash or lag my macbook pro? My system is 2.66GHz and 320GB, bought in oct 2009 mbp. Many thanks.