Problems installing Cisco VPN client – resolved

I’ve had this problem for over a year now. At the last client where I worked I was given a Cisco VPN client to install on my laptop, but unfortunately I couldn’t install it. I ended up using an alternate VPN client (ShrewSoft) to get round the problem.

When installing the Cisco client, I kept getting the error “Error 27850. Unable to manage networking component. Operating system corruption may be preventing installation.”

I finally found an article on the Cisco support website explaining that the problem is related to the number of filters that Windows can apply to a network adapter. By installing lots of different virtual network adapters and other bits of obscure networking software, the inbuilt limit within Windows can easily be exceeded.

VPN installation error


I found this article which suggested that the reason might be due to the large number of VPN clients and virtual network adapters installed…

I concluded that the ShrewSoft client “knows” to increase the relevant registry setting but the Cisco client isn’t as “intelligent”.

When I checked this registry key – HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlNetworkMaxNumFilter

I could see that my “MaxNumFilter” setting was set to 9. I changed this to 14 (decimal) and hey presto I could install the client with no problem.

My laptop now has Windows 7 x64 / Oracle Virtual Box / VMWare Player / Connectify / ShrewSoft VPN client and Cisco VPN client all co-existing happily.

Author: Richard Bishop