This problem occurs due to a registry error in the installer. All you need to do is fix the following registry key:
regedit.exe, and go to
DisplayName value to remove the gibberish before "Cisco". The value by default will be something like:
@oem18.inf,%CVirtA_Desc%;Cisco Systems VPN Adapter for 64-bit Windows
Edit it to just say:
Cisco Systems VPN Adapter for 64-bit Windows
You can also save the following as a
.reg file, and open it to fix the registry problem automatically:
Windows Registry Editor Version 5.00
"DisplayName"="Cisco Systems VPN Adapter for 64-bit Windows"
Update: this was working for several months, but recently has been having intermittent issues. The VPN will connect "successfully", and the network remains connected, but no servers are accessible. I've been using the Cisco AnyConnect VPN lately, and the most recent version appears to work on Windows 8 x64. I couldn't find any place to publicly download the AnyConnect client though, so you will need to obtain it from your organization's IT department.