Step 1: From the "Start Menu", select "Control Panel". From there, Select "Network and Internet". On this menu, select "Network and Sharing Center". From here, "Set up a new connection or network". You will then select "Connect to a workplace" and from there "Use My Internet Connection (VPN)".
Step 2: In the "Internet Address" box, type in the DNS Name or the IP Address that you are attempting to connect to. Type in a descriptive name in the "Destination Name" box. Check the "Don't connect now, just set it up so I can connect later" box then click "Next".
Step 3: Type in your User Name and Password for the Client you are attempting to connect to then click "Create".
Step 4: Return to the "Network and Sharing Center". Select "Connect to a Network". On the window that appears, select the VPN Connection you just created and click "Connect". On the next menu, select "Properties".
Step 5: Move to the "Security" tab. In the "Type of VPN" list, select "Layer 2 Tunneling Protocol with IPsec (L2TP/IPSec)". In the "Data Encryption" list, select "Require Encryption (disconnect if server declines)". Select "Allow these protocols" and make sure "Microsoft CHAP Version 2 (MS-CHAP v2)" is the only option selected. Return to the "Type of VPN" list and select the "Advanced Settings" button.
Step 6: Select the "Use Preshared Key for Authentication" and type in the Pre-Shared key (Also known as the 'Shared Secret') provided to you from the client you're attempting to connect to. Then click the "OK" button.
Step 7: Return to the "Network and Sharing Center", select the VPN Connection you created and select "Connect". If you've followed these steps correctly, the connection should be properly established.