Can't re-install PD 5160 on Leopard 9a527

Hello,

I uninstalled because of the "Can't communicate with hypervisor" message.
I did it as described in parallels support.

When i run the installer program freezes at the beggining of the installation script and registry says:

"Sep 21 23:41:10 manuel runner[497]: preflight[502]: can't add kext (file access/permissions)."

I repaired permissions before I run the installation.

I can't write in the Startupitems and Extension folders.

Thanks. Gracias