To re-create the Outlook Web Access (OWA) virtual directories in Microsoft Exchange 2003 they should be deleted follwed by restarting the IS and System attendant Exchange services. This can be perform with the following commands:

cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/Exadmin
cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/Exchange
cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/ExchWeb
cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/Microsoft-Server-ActiveSync
cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/OMA
cscript %windir%\\system32\\iisvdir.vbs /delete w3svc/1/root/Public
cscript %systemdrive%\\inetpub\\adminscripts\\adsutil.vbs delete ds2mb
net stop "microsoft exchange information store"
net stop "microsoft exchange system attendant"
net start "microsoft exchange system attendant"
net start "microsoft exchange information store"