After you have prepare the server, let start the TMG installation.
1. Click on Install Forefront TMG when you run the splash file. The system will perform preparation tools check.
2. Once the check is complete, Tick Launch Microsoft Forefront TMG Setup and Click Finish.
3. The system will display Microsoft Forefront TMG installation wizard.
4. Accept the license agreement
5.Enter customer information and product key
6.Specify the installation path
7.Specify the address range for Internal Network. Click Browse
8.Click Add range to add your subnet range
9. Service Warning is indicated that the TMG installation will restart the following services as listed in below figure
10.Click Next to start the installation
11. The installation is complete. Click Finish to end the installation wizard