How to delete a broker that is creating trouble to delete?

1. C:\ProgramData\IBM\MQSI

       There remove the Broker name in the Common,Config,registry folders

2. Queue Manager Deletion in Win 7
     C:\Program Files (x86)\IBM\WebSphere MQ\Qmgrs

Deleting Brokers path in Windows 7

C:\Program Files (x86)\IBM\WebSphere MQ\Qmgrs
C:\ProgramData\IBM\MQSI\components


Another case is when we change the System Password also,Broker does not start & connect to queue manager.In that case goto Run-->Services.msc & make sure that three of them are in started state or else delete the broker & queue manager using the above steps & create a new broker using Default Configuration wizard.

Now change the password here also to the newly changed password