Security update KB2977320 appears to hang

Hi,

I'm manually applying the Security Update for SQL Server 2008 R2 Service Pack 2 (KB2977320). The progress bar never gets off it's start point.  30 minutes after pressing the Install Button, I check the Windows update log and see the following :-

2015-02-01        22:45:55:191         460        11dc        AU        #############

2015-02-01        22:45:55:191         460        11dc        AU        ## START ##  AU: Install updates

2015-02-01        22:45:55:191         460        11dc        AU        #########

2015-02-01        22:45:55:194         460        11dc        AU         # Initiating manual install

2015-02-01        22:45:55:194         460        11dc        AU         # Approved updates = 1

2015-02-01        22:45:55:195         460        11dc        AU        <<## SUBMITTED ## AU: Install updates / installing updates [CallId = {F9E58F4D-8CCB-4BAE-96BF-7CBB619ED4EC}]

2015-02-01        22:45:55:195         460        13a8        Agent        *************

2015-02-01        22:45:55:195         460        13a8        Agent        ** START **  Agent: Installing updates [CallerId = AutomaticUpdates]

2015-02-01        22:45:55:195         460        13a8        Agent        *********

2015-02-01        22:45:55:195         460        13a8        Agent         * Updates to install = 1

2015-02-01        22:45:55:198         460        13a8        Agent         *   Title = Security Update for SQL Server 2008 R2 Service Pack 2 (KB2977320)

2015-02-01        22:45:55:198         460        13a8        Agent         *   UpdateId = {285B2EA3-C342-47E9-97B0-65D68C13F3BD}.200

2015-02-01        22:45:55:198         460        13a8        Agent         *     Bundles 1 updates:

2015-02-01        22:45:55:198         460        13a8        Agent         *       {1B81973B-445B-4B03-A5AB-83D97845CA42}.200

2015-02-01        22:45:55:201         460        13a8        Agent        WARNING: failed to calculate prior restore point time with error 0x80070002; setting restore point

2015-02-01        22:45:55:202         460        13a8        Agent        WARNING: LoadLibrary failed for srclient.dll with hr:8007007e

2015-02-01        22:45:55:202         460        13a8        Handler        Attempting to create remote handler process as <xxxxxxxx>  in session 2

2015-02-01        22:45:55:203         460        11dc        AU        Getting featured update notifications.  fIncludeDismissed = true

2015-02-01        22:45:55:203         460        11dc        AU        No featured updates available.

2015-02-01        22:45:55:208         460        11dc        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:55:628         460        13a8        DnldMgr        Preparing update for install, updateId = {1B81973B-445B-4B03-A5AB-83D97845CA42}.200.

2015-02-01        22:45:56:216         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:57:198         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:57:230         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:58:244         460        11dc        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:59:212         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:45:59:257         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:00:270         460        11dc        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:01:221         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:01:284         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:01:317        3424        1e0        Misc        =========== Logging initialized (build: 7.6.7600.256, tz: -0000)  ===========

2015-02-01        22:46:01:317        3424        1e0        Misc         = Process: C:\Windows\system32\wuauclt.exe

2015-02-01        22:46:01:317        3424        1e0        Misc         = Module: C:\Windows\system32\wuaueng.dll

2015-02-01        22:46:01:307        3424        1e0        Handler        :::::::::::::

2015-02-01        22:46:01:317        3424        1e0        Handler        :: START ::  Handler: Command Line Install

2015-02-01        22:46:01:317        3424        1e0        Handler        :::::::::

2015-02-01        22:46:01:317        3424        1e0        Handler         : Updates to install = 1

2015-02-01        22:46:02:339         460        11dc        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:03:235         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:03:313         460        16a0        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:04:327         460        11dc        AU        All updates already downloaded, setting percent complete to 100

2015-02-01        22:46:05:246         460        11dc        AU        All updates already downloaded, setting percent    ......

The log is full of these messages and the update process appears to be looping.

I can of course stop the installation but then SQL returns the following message when a login is attempted :-

Login failed for user 'sql_agent_user'. Reason: Server is in script upgrade mode. Only administrator can connect at this time.

Can anyone help please ?

Thanks

Richard