I was running Parallels 4.0.3846 and XP without problems. I then upgraded to OS X 10.5.8 Leopard, NOT snow leopard) by archive and install. Parallels wouldn't start up. looking at the forums it appears that "archive and install" results in problems with parallels. so, I downloaded 4.0.3846 from the website and reinstalled parallels. parallels now starts and windows runs but when I try to install/reinstall tools I get the following message: "unable to download the installation package". how do I resolve this? thanks, Pete OS X 10.5.8 macbook pro 3 gb ram