I've inherited an attempted Exchange 2010 implementation from a colleague that apparently failed. I've almost managed to bring it back from the dead, but the Hub Transport role fails to install with the following error

[10/06/2012 02:30:44.0119] [2] Beginning processing Set-LocalPermissions -Feature:'Bridgehead'
[10/06/2012 02:30:44.0166] [2] [ERROR] Unexpected Error
[10/06/2012 02:30:44.0166] [2] [ERROR] The registry key "SOFTWARE\Microsoft\ExchangeServer\v14\Transport" does not exist under "HKEY_LOCAL_MACHINE".
[10/06/2012 02:30:44.0182] [2] Ending processing Set-LocalPermissions
[10/06/2012 02:30:44.0182] [1] The following 1 error(s) occurred during task execution:
[10/06/2012 02:30:44.0182] [1] 0.  ErrorRecord: The registry key "SOFTWARE\Microsoft\ExchangeServer\v14\Transport" does not exist under "HKEY_LOCAL_MACHINE".
[10/06/2012 02:30:44.0182] [1] 0.  ErrorRecord: System.ArgumentException: The registry key "SOFTWARE\Microsoft\ExchangeServer\v14\Transport" does not exist under "HKEY_LOCAL_MACHINE".
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.GetTargetRegistryKey(XmlNode targetNode)
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.ChangePermissions[TTarget,TSecurity,TAccessRule,TRights](XmlNode targetNode, Dictionary`2 rightsDictionary, GetTarget`1 getTarget, GetOrginalPermissionsOnTarget`2 getOrginalPermissionsOnTarget, SetPermissionsOnTarget`2 setPermissionsOnTarget, CreateAccessRule`2 createAccessRule, AddAccessRule`2 addAccessRule, RemoveAccessRuleAll`1 removeAccessRuleAll)
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.SetPermissionsOnCurrentLevel[TTarget,TSecurity,TAccessRule,TRights](XmlNode permissionSetNode, String targetType, Dictionary`2 rightsDictionary, GetTarget`1 getTarget, GetOrginalPermissionsOnTarget`2 getOrginalPermissionsOnTarget, SetPermissionsOnTarget`2 setPermissionsOnTarget, CreateAccessRule`2 createAccessRule, AddAccessRule`2 addAccessRule, RemoveAccessRuleAll`1 removeAccessRuleAll)
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.SetPermissionsOnCurrentLevel(XmlNode permissionSetNode)
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.SetFeaturePermissions(String feature)
   at Microsoft.Exchange.Management.Deployment.SetLocalPermissions.InternalProcessRecord()
[10/06/2012 02:30:44.0197] [1] [ERROR] The following error was generated when "$error.Clear(); 
    Set-LocalPermissions -Feature:"Bridgehead"

" was run: "The registry key "SOFTWARE\Microsoft\ExchangeServer\v14\Transport" does not exist under "HKEY_LOCAL_MACHINE".".
[10/06/2012 02:30:44.0197] [1] [ERROR] The registry key "SOFTWARE\Microsoft\ExchangeServer\v14\Transport" does not exist under "HKEY_LOCAL_MACHINE".
[10/06/2012 02:30:44.0197] [1] [ERROR-REFERENCE] Id=BridgeheadLocalPermissionsComponent___2e2dbc2a97cb4429bc2074edc50bedbd Component=EXCHANGE14:\Current\Release\Shared\Datacenter\Setup
[10/06/2012 02:30:44.0197] [1] Setup is stopping now because of one or more critical errors.
[10/06/2012 02:30:44.0197] [1] Finished executing component tasks.
[10/06/2012 02:30:44.0244] [1] Ending processing Install-BridgeheadRole

I've been unable to find any documentation on how to resolve this issue. Any help would be appreciated.