The ISA Server 2006 Management Pack for Microsoft System Center Operations Manager 2007 does not discover the firewall role when ISA Server is installed in a workgroup. Specifically, the script FirewallServerRoleDisc.vbs fails with this event:
FirewallServerRoleDisc.vbs : Error - Number:-1073478746 Source:FPC.Root.1 Description:The property or method Arrays is not supported when the ISA Server computer is not connected to a Configuration Storage server.
This occurs because the account that runs the script does not have the necessary permissions to perform the operation.
The topology details for this scenario are:

·         The Configuration Storage Server is a domain member

·         The ISA Server computer is in a workgroup

·         The Action Account configured for Microsoft Operations Manager is Local System.

To avoid or correct this situation, follow this procedure:

1.       Create a Local Admin Account on the Configuration Storage Server

2.       Create a Local Admin Account on the ISA Server computer with the same name and password from Step 1. Repeat this steps for each ISA Server computer -  basically ,mirror the accounts.

3.       On the Operations Manager Console

i)                    Click  Administration Node,  select  Run As Accounts and then Accounts.

ii)                   Create a new Run As Account , with the Type Action Account. Complete the other Details and then click Next.

iii)                 Specify the domain credentials and the ISA Server computer name.

iv)                 Click Next and create the account.

4.       On the Operations Manager Console

i)                    Click  Administration Node,  select  Run As Accounts and then Profiles.

ii)                   Double click Default Action Account.

iii)                 On the Add Run As Accounts dialog box , select the firewall and click Edit.

iv)                 In the Run As Account drop down , choose the Action Account created in the previous steps.

5.       Restart the System Center Management or Health Service on the ISA Server computer.

After this procedure the script should work and firewall role should be discovered.