The Deep Security Agent (DSA) with NDIS 5.1 or 6.0 driver has been fixed so that the driver will free all packets correctly before upgrading or uninstalling.
However, when installing or uninstalling NDIS drivers, Microsoft requires that all NDIS drivers be unbound and then rebound. This means that if other third-party NDIS drivers do not properly free packets, it is still possible for the DSA installation, upgrade or uninstallation to hang.
This is beyond our control and will only happen in very limited situations. If this issue occurs, you need to reboot the machine. Rebooting will likely resolve the issue with a reattempt to install, uninstall or upgrade afterwards.