Installation Alert won't go away After a failed installation of updates the following alert won't go away.  It gives me no option to cancel.  Any ideas on how to get rid of it short of rebooting the machine?  Using OSX 10.9.4.

Please advise.
Start Activity Monitor (from Launchpad/Other or via Spotlight).

Find iTunes in the list and close it. If it's not there then find iTunes Helper and close that.

The names are present in the Process Name column, closing the processes is possible via the X button situated around the top left corner (of course not the red one, which closes the Activity Monitor itself, but below that).