I've been using Vmware for the past 2 years for beta testing, but I've done very little malware testing. I have the concern that the guest OS will allow cross contamination of the host OS. What are the chances of this happening? Are there steps that need to be taken to prevent this? Do I need to adjusting any settings of VMware to prevent cross contamination? I'm using the latest version of VMware Workstation. I use Shadow User on XP Pro 32 bit for beta testing because it allows saving changes to the shadow after reboot, but I can't use Shadow User on W7. I'm using W7 64 bit as the host OS.