Log on to the Web server computer as an administrator.
Click Start, point to Settings, and then click Control Panel.
Double-click Administrative Tools, and then double click Internet Services Manager.
Select the Web site from the list of different served sites in the left pane.
Right-click the Web site, folder, or file for which you want to configure SSL communication, and then click Properties.
Click the Directory Security tab.
Click Edit.
Click Require secure-channel (SSL) if you want the Web site, folder, or file to require SSL communications.
Click Require 128-bit encryption to configure 128-bit (instead of 40-bit) encryption support.
To allow users to connect without supplying their own certificate, click Ignore client certificates.
Alternatively, to allow a user to supply their own certificate, use Accept client certificates.
To configure client mapping, click Enable client certificate mapping, and then click Edit to map client certificates to users.