Bu ozellik Server 2008 uzerindeki IIS 7.0'dan tamamen kaldırıldı yani normal yollar ile cozemezsiniz. Fakat asagidaki gibi bir workaround u var ise yarayacaktir:

Though it is NOT supported, here is the workaround:

1. On your IIS7 (Windows 2008) server, navigate to
c:\windows\system32\inetsrv and create a folder named IISADMPWD
2. Copy the files from the IISADMPWD folder from an IIS 6.0 (Windows 2003)
server and paste them under the IISADMPWD folder you just created.
3. Open IIS Manager, and expand [server name] > Sites
4. Right click on default website and select Add Virtual Directory
5. Type IISADMPWD for the alias and "c:\windows\system32\inetsrv\IISADMPWD&quo t;
for the physical path then click OK
6. Right click on the IISADMPWD virtual directory and select Convert to
Application

7. The Add application dialog box opens, click on the select button and
choose MSExchangeOWAAppPool
8. Click OK twice to return to IIS7 Manager
9. Click on IISADMPWD folder and on the right pane, click on Authentication
10. Make sure Windows Authentication is set to Enabled, click OK (The
Authentication can be changed to Basic or Anonymous as well)
11. Close IIS7 Manager
12. Restart IIS (iisreset)

You could also check KB 833734 (http://support.microsoft.com/kb/833734) if
you run into any issues after following the above steps.

Emre AYDIN