Can't Profile Web Application

When I try to start profiling my web application in IIS, I get the error "Failed to connect to target process because an exception occurred: Could not start IIS. Please check your settings and try again." I pasted the exception details below.

• I'm running ANTS as administrator.
• I'm using ANTS Performance Profiler 7.4
• I'm running Windows 7 with IIS7

It was working for me some moths ago. Then I didn't use it for a while, and now I need to use it again, but I'm getting this error. I can't think of anything in particular that I have changed, but I guess something is different.

Any suggestions?

Exception Details:
Could not start IIS.
RedGate.Profiler.Engine.Exceptions.CannotStartSessionException
at ..Launch()
at ?..?()

Caused by:

Could not start IIS.
RedGate.Profiler.Engine.Exceptions.CannotStartIisSessionException
at ..()
at ..Launch()

Caused by:

Timed out waiting for port 7151 on 127.0.0.1 to become available
RedGate.Profiler.Engine.Exceptions.CannotStartIisSessionException
at ?.?.??()
at ..??( )
at ..()

Caused by:

Timed out waiting for port 7151 on 127.0.0.1 to become available
RedGate.Profiler.Engine.Startup.IIS.PortTimeoutException
stack trace:
at RedGate.Profiler.Engine.Startup.IIS.IISUtilities.WaitForPort(IPAddress address, Int32 port, Int32 timeout)
at RedGate.Profiler.Engine.Startup.IIS.IISUtilities.WaitForPort(String hostname, Int32 port, Int32 timeout)
at ..StartProfilingIIS(String , String )
at RedGate.Profiler.Engine.Startup.IIS.IISStarter`1.StartProfilingIIS(String currentUserName, String subprocessVariableValue)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg, Int32 methodPtr, Boolean fExecuteInContext)
rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at RedGate.Profiler.Engine.Startup.IIISActuator`1.StartProfilingIIS(String currentUserName, String subprocessVariableValue)