Windows – No Internet connection after upgrade to Windows 10

The Cisco VPN has not yet been updated for Windows 10 and is incompatible with the OS.

Microsoft has shared a KB that should fix this. the KB can be found at https://support.microsoft.com/en-us/kb/3084164

Resolution

To resolve this issue, follow these steps:

Open an administrative Command Prompt window. Run the following commands:

reg delete HKCR\CLSID\{988248f3-a1ad-49bf-9170-676cbbc36ba3} /f

netcfg -v -u dni_dne

NOTE: this requires changing your registry information. Make sure you backup your registry before executing this.

Getting your network connections back

I had the same problem on a Lenovo Yoga 2 Pro. I got my network devices by running the following in an Administrator command prompt:

netcfg -s n
reg delete HKCR\CLSID\{988248f3-a1ad-49bf-9170-676cbbc36ba3} /va /f
netcfg -v -u dni_dne

It has to do with the legacy Cisco VPN client:

We believe in cases where there is a Legacy Cisco VPN that the filter driver is only migrated partially. This filter driver is marked as Mandatory and causing issues with the Network Interfaces. There is a fix in the pipeline that blocks this particular version of the Cisco VPN solution that has this Filter driver from upgrading. The latest versions of Cisco VPN do not have this driver.

Reinstalling the Cisco VPN Client

If you get this error when trying to install the Cisco VPN client:

Error 27850. Unable to manage networking component. Operating system corruption may be preventing installation.

...then it's time to reinstall DNE.

1. Download and install winfix.exe from http://www.citrix.com/go/lp/dne.html
2. Reboot.
3. Download and install dneupdate.msi (32-bit) or dneupdate64.msi (64-bit)
4. Reboot.

Now you should be able to reinstall the VPN Client.

Re: registry

One piece of advice was to change the registry key for HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Network\MaxNumFilters from 8 to 14. I didn't have this key on Windows 10, and when I created it (with a value of 14), it didn't solve the problem.