Installing Exchange 2010 with Server 2008 R2 Virtaulbox

hai i am intsalling Exchange 2010 and need ur help..

at the time of installing MS Exchange 2010 iam getting one error... full description of that error is as under :-

error 

the following error was generated when "$error.clear:if ($Role start ransport service) {start .setup service.service name MS Exchange Transport} "was run:"service" MS Exchange Transport.failed to reach status"running on this server."

service "MS exchange transport" failed to reach status "Running" on this server.

The following error was generated when "$error.Clear(); if ($RoleStartTransportService) { start-SetupService -ServiceName MSExchangeTransport }" was run:"Service 'MSExchangeTransport' failed to start. Check the event log for possible reasons for the service start failure.". Service 'MSExchangeTransport' failed to start. Check the event log for possible reasons for the service start failure

Elased time :00:12:16

please help!