Receiving VPN Error Message: Reason 442: Failed to enable Virtual Adapter.

Hi,

I would suggest you to follow the troubleshooting steps and check if the issue on your computer gets resolved.

If you are using Cisco product:

Duplicate IP Address Triggers Error 442 on Windows 7

The following error "Reason 442: failed to enable virtual adapter" appears after Windows 7 reports a duplicate IP address detected. Subsequent connections fail with same message, but Windows 7 doesn't report a duplicate IP address detected.

To work around error 442, do the following steps:

Step 1Open "Network and Sharing Center".

Step 2Select "Manage Network Connections".

Step 3Enable the Virtual Adapter ("VA"—Cisco VPN Adapter).

Step 4Right-click on Cisco VPN Adapter and select "Diagnose" from the context menu.

Step 5Select "Reset the network adapter Local Area Connection X".

If this procedure does not work, run the following command from cmd:

reg add HKLM\System\CurrentControlSet\Services\Tcpip\Parameters /v ArpRetryCount /t REG_DWORD /d 0 /f

Then reboot.

This resolves the issue until Windows 7 reports a duplicate IP address again. Follow the preceding steps to resolve it again.

If that doesn't work, you might have UAC enabled. If so, you must run cmd as administrator and repeat the previous registry workaround.

From the following:

http://www.cisco.com/en/US/docs/security/vpn_client/cisco_vpn_client/vpn_client500_501/release/notes/51client.html#wp1584552

Hope this information helps you.