Form Template's status remains forever in 'installing' or 'deleting' state

Form template’s status never leaves “Installing…”, “Deleting…”, “Upgrading…”  or “Removing…” states
These states seem to indicate that you're running a multiple-machine server farm, and on your server farm, you're running into some issues in propagating changes to all of the machines.  If you have not done so already, I highly recommend turning on the following services on each machine: SPAdmin, and SPTimerV3 You can do this by running:

                net start SPTimerV3
                net start SPAdmin

On each machine (If you are doing this on a SharePoint Farm , you want to make sure the Timer Service is running on all the Servers on the Farm).  Net start is a ensure semantic, so this will not inadvertently toggle or cause any damage if run on a machine where the service is already started.  Now that that's done, you can go on to correcting the problems that you have.
From Central Administration, go to the Operations page, under the Global configuration group, click on Timer Job Status.  On that page, look for timer jobs that have the name in the following formatting.  If you filename is FOO.xsn, it will look like:
Windows SharePoint Services Solution Deployment for "form-FOO.wsp"
See if there was a failure.  If so, go back a page, and go to Timer Job Definitions.  Drill down in the timer job definition that you care about and you can perform the following:

Generally:

1. Try to restart the job if that is available.
2. If restart is not available, delete the job, then attempt your initial action again .