This is the error in the install log.
[ERROR] An error occurred while creating the IIS virtual directory 'IIS://SRV1.TCHBONISA.local/W3SVC/1/ROOT/owa' on 'SRV1'.
[2010/02/20 06:54:42 PM] [2] [ERROR] Cannot create a file when that file already exists. (Exception from HRESULT: 0x800700B7)
[2010/02/20 06:54:42 PM] [2] Ending processing.
[2010/02/20 06:54:42 PM] [1] The following 1 error(s) occurred during task execution:
[2010/02/20 06:54:42 PM] [1] 0. ErrorRecord: An error occurred while creating the IIS virtual directory 'IIS://SRV1.TCHBONISA.local/W3SVC/1/ROOT/owa' on 'SRV1'.
[2010/02/20 06:54:42 PM] [1] 0. ErrorRecord: System.InvalidOperationException: An error occurred while creating the IIS virtual directory 'IIS://SRV1.TCHBONISA.local/W3SVC/1/ROOT/owa' on 'SRV1'. ---> System.Runtime.InteropServices.COMException (0x800700B7): Cannot create a file when that file already exists. (Exception from HRESULT: 0x800700B7)
at System.DirectoryServices.Interop.UnsafeNativeMethods.IAdsContainer.Create(String className, String relativeName)
at System.DirectoryServices.DirectoryEntries.Add(String name, String schemaClassName)
at Microsoft.Exchange.Management.Metabase.IisUtility.CreateVirtualDirectory(DirectoryEntry parentWebDir, String path, String name)
at Microsoft.Exchange.Management.Metabase.IisUtility.CreateWebDirObject(String parent, String path, String vdirName)
at Microsoft.Exchange.Management.Metabase.CreateVirtualDirectory.Execute()
at Microsoft.Exchange.Management.SystemConfigurationTasks.NewExchangeVirtualDirectory`1.CreateToMetabase()
at Microsoft.Exchange.Management.SystemConfigurationTasks.NewExchangeVirtualDirectory`1.InternalProcessRecord()
--- End of inner exception stack trace ---
[2010/02/20 06:54:42 PM] [1] [ERROR] An error occurred while creating the IIS virtual directory 'IIS://SRV1.TCHBONISA.local/W3SVC/1/ROOT/owa' on 'SRV1'.
[2010/02/20 06:54:42 PM] [1] [ERROR] Cannot create a file when that file already exists. (Exception from HRESULT: 0x800700B7)
[2010/02/20 06:54:42 PM] [1] Setup is halting task execution because of one or more errors in a critical task.
[2010/02/20 06:54:42 PM] [1] Finished executing component tasks.
[2010/02/20 06:54:42 PM] [1] Ending processing.
[2010/02/20 06:55:34 PM] [0] End of Setup
[2010/02/20 06:55:34 PM] [0] **********************************************