I think I might be doing this wrong, I extracted the EXE so I can get to the MSI then created my GPO to deploy the package. Took a couple reboots before the package installer interface popup and just went away but nothing gets installed. 

All the machines have SEP11 on them that was previously installed manually and not through group policy. I can run the MSI manually and successfully installed SEP12. 

Is it possible to deploy SEP12 through GPO completely silent and force reboot?  Can you point me to the right direction? thanks!

Is there a failure log to review? anything in event viewer?

There are a couple errors

Log Name:      System
Source:        Application Management Group Policy
Date:          2/25/2015 1:21:57 PM
Event ID:      102
Task Category: None
Level:         Error
Keywords:      Classic
User:          XXXX
Computer:      CXXX
Description:
The install of application Symantec Endpoint Protection from policy SEP12 Deployment failed.  The error was : %%1603
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Application Management Group Policy" />
    <EventID Qualifiers="0">102</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2015-02-25T21:21:57.000000000Z" />
    <EventRecordID>40777</EventRecordID>
    <Channel>System</Channel>
    <Computer>Cxxxxxxx</Computer>
    <Security UserID="S-1-5-21-850837630-2931231608-2184496696-1107" />
  </System>
  <EventData>
    <Data>Symantec Endpoint Protection</Data>
    <Data>SEP12 Deployment</Data>
    <Data>1603</Data>
  </EventData>
</Event>

Log Name:      System
Source:        Application Management Group Policy
Date:          2/25/2015 1:21:57 PM
Event ID:      108
Task Category: None
Level:         Error
Keywords:      Classic
User:          XXXXXX
Computer:      XXXX
Description:
Failed to apply changes to software installation settings.  Software changes could not be applied.  A previous log entry with details should exist.  The error was : %%1603
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Application Management Group Policy" />
    <EventID Qualifiers="0">108</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2015-02-25T21:21:57.000000000Z" />
    <EventRecordID>40778</EventRecordID>
    <Channel>System</Channel>
    <Computer>XXXXXXX</Computer>
    <Security UserID="S-1-5-21-850837630-2931231608-2184496696-1107" />
  </System>
  <EventData>
    <Data>Software changes could not be applied.  A previous log entry with details should exist.</Data>
    <Data>1603</Data>
  </EventData>
</Event>

May be the package is corrupt you can create the msi package agin and try it

Creating a managed .MSI package in Symantec Endpoint Protection 12.1

I was afraid you'd ask me to do something like that. I was only given the setup.exe it would take longer to get any other SEP tools from the POC than it would to deploy this on the 200 computers manually one by one. LOL I think i'm SOL

But run the same package locally and it works?

Hey dannie,

For using GPO i suggest to create one for call a script and check versions to quit or install, if necessary.

You can use a Computer Policies to create a shutdown script. For silent mode you need to create a silent package for SEP and call it. You dont need a reboot, cuz u have installed on shutdown. 

Create a .bat or .vbs to check if an registry exists and run a package.

WshShell.RegRead("HKLM\SOFTWARE\Symantec\Symantec Endpoint Protection\SMC\ProductVersion")

I using here in my environment (13k clients / 350 remote locations) and works great.

Regards