Multiple Certificate on MS ISA Server

add the AllowPerServercertificate registry entry, follow these steps:

1.

Click Start, click Run, type regedit in the Open box, and then click OK.

2.

Locate and then click the following registry subkey:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fpc\w3proxy 

3.

On the Edit menu, point to New, and then click DWORD Value.

4.

Type AllowPerServercertificate, and then press ENTER.

5.

Right-click AllowPerServercertificate, and then click Modify

6.

Type 1 in the Value data box, and then click OK.

7.

Quit Registry Editor.

8.

After you add the AllowPerServercertificate Registry entry, restart the Firewall service.