so i had to do a clean install of lion and PD7. OS X 10.7.3 2.4 GHz Core 2 Duo 4GB RAM 220GB free on HD after install, i got the message about hypervisor not being enabled. uninstalled PD7. reinstall PD7 and now during installation get the following network-related messages: System Extension cannot be used The system extension "/System/Library/Extensions/prl_netbridge.kext" was installed improperly and cannot be used. and System Extension cannot be used The system extension "/System/Library/Extensions/prl_vnic.kext" was installed improperly and cannot be used. i have uninstalled and re-installed PD7 twice now and the same error occurs. parallels starts up, the VM starts up, but it's painfully slow and unusable. network is unavailable. any help is appreciated.
try to use this kB http://kb.parallels.com/en/112189 to remove all instances of PD and install it back afterwards.