How to fix “Install-SPSolution: Admin SVC must be running in order to create deployment timer job”

http://ybbest.wordpress.com/2011/09/10/how-to-fix-%E2%80%9Cinstall-spsolution-admin-svc-must-be-running-in-order-to-create-deployment-timer-job%E2%80%9D/

How to fix “A deployment or retraction is already under way for the solution “*.wsp”, and only one deployment or retraction at a time is supported”

http://ybbest.wordpress.com/2011/09/10/how-to-fix-%E2%80%9Ca-deployment-or-retraction-is-already-under-way-for-the-solution-%E2%80%9C-wsp%E2%80%9D-and-only-one-deployment-or-retraction-at-a-time-is-supported%E2%80%9D/