while install Cisco VPN client for windows. it very often causes blue screen on newly purchased laptops.
i had tried several version, 4.6 or 4.8. all causes blue screen on windows xp on D520/530/D420 computers that purchased in recent years.

there is a solution that the IT staff from a sister company told me:
disable the vsdatant device in the device manager.

this is a hidden device, in order to find it, you need select "view' >"devices by connection" in the device manager, then select "view"> "show hidden devices".
from the right panel near the bottom, you can find it, right click the "vsdatant" then select disable.
please reboot computer before connect VPN.