The solution cannot be removed when a job is scheduled or running

The solution cannot be removed when a job is scheduled or running
Cancel Deployment when a error is occured like
The solution cannot be removed when a job is scheduled or running

Open command prompt and enumerate the running deployments by executing this command: 
stsadm -o enumdeployments

then iisreset

Now, we obtain the jobid and cancel this deployement as follows:
stsadm -o canceldeployment -id 2529c788-971c-46a3-b69f-a2a0a1fcc851
That's it. We can then retract and delete the solution.