Error Installing Cisco AnyConnect VPN Client: “The file ‘Manifest Tool.exe’ is not marked for installation”

Click Start and type “regedit” in the box.

A dialogue box will pop up with the following text: Do you want to allow the following program to make changes to this computer?
Click Yes.

Browse to the following location: HKEY_CLASSES_ROOT\Installer\Products\

Within the Products folder, locate and delete the registry key which contains product information for Cisco AnyConnect. (We recommend making a backup of this registry key before deleting it.)

Each registry key within Products is an alphanumeric string. Select the first key and look on the right side for ProductName REG_SZ Cisco AnyConnect. Go through each key in the Products folder until you find the one for Cisco AnyConnect.

For example,

the registry key for Cisco AnyConnect v4.4 is named 31D43F43B3678C84490E6DDCF38F2486

the registry key for Cisco AnyConnect v4.5 is named 89A926BE96E58E04ABE93C3998F959D9

Each version of Cisco AnyConnect will have a different name for this registry key.

Close the registry editor.

Install the latest version Cisco AnyConnect.