There’s a conflict between Comodo Firewall and the built-in firewall in Cisco’s VPN client which can cause blue screens. You’ll see a DRIVER_IRQ_NOT_LESS_OR_EQUAL error caused by inspect.sys or vsdatant.sys.

One way to work around it is to install the VPN client without the built-in firewall: msiexec.exe /i vpnclient_setup.msi DONTINSTALLFIREWALL=1

The other way is to remove vsdata.dll, vsinit.dll and vsdatant.sys from the Windows\System32 directory.