Failure running psconfig for Sharepoint 2010

My situation is I'm working at a consulting company that provides IT support for a number of small-to-medium size local businesses. We have a customer running SBS 2011, which includes SharePoint 2010 by default. The customer has not used SharePoint yet, but some SP uppdates got applied somewhere along the way, psconfig wasn't run at that time, and now the Volume Shadow Copy service is failing, along with backup jobs in Backup Exec. I ran the
(get-spserver $env:computername).NeedsUpgrade query in the SP comand shell and got a "True" response.

So, yesterday evening I tried running PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures on the affected server.  It got about halfway through and failed. I rebooted and tried it again, with the same result.  I'll paste in the command line text below. 

Basically we need to know our best course of action from here. The customer hasn't used SharePoint yet, but does think they may use it in the future. Would a good resolution of our current problem be to just completely uninstall SharePoint and then reinstall it?

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN>PSCo
nfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd
installfeatures
SharePoint Products Configuration Wizard version 14.0.6009.1000. Copyright (C) M
icrosoft Corporation 2010. All rights reserved.

Performing configuration task 1 of 6
Initializing SharePoint Products upgrade...

Waiting to get a lock to upgrade the farm.

Successfully initialized SharePoint Products upgrade.

Performing configuration task 2 of 6
Initiating the upgrade sequence...

Successfully initiated the upgrade sequence.

Performing configuration task 3 of 6
Registering SharePoint features...

Successfully installed feature C:\Program Files\Common Files\Microsoft Shared\We
b Server Extensions\14\Template\Features\ReportServerStapling\Feature.xml.

Successfully registered SharePoint features.

Performing configuration task 4 of 6
Installing the application content files...

Installing the SharePoint Central Administration Web Application content files..
.

Installing the SharePoint Web Application content files...

Failed to install the application content files.

An exception of type System.IO.InvalidDataException was thrown.  Additional exce
ption information: The web configuration file, C:\Program Files\Common Files\Mic
rosoft Shared\Web Server Extensions\14\config\Webconfig.rs.xml, does not have el
ement "configuration/configSections/sectionGroup[@name='SharePoint']" or it is i
nvalid.

Total number of configuration settings run: 4
Total number of successful configuration settings: 3
Total number of unsuccessful configuration settings: 2
Successfully stopped the configuration of SharePoint Products.
Configuration of SharePoint Products failed.  Configuration must be performed be
fore you use SharePoint Products.  For further details, see the diagnostic log l
ocated at C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\1
4\LOGS\PSCDiagnostics_6_12_2014_17_31_19_873_320658344.log and the application e
vent log.

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN>