Download the latest MSI from:
http://www.adobe.com/products/players/flash-player-distribution.html
(Apply to distribute Flash Player – Fill fields – Accept and Submit)
You will find download link in the email.

Download InstEd (MSI Editor)
http://www.instedit.com/download.html

or google “Adobe customization wizard”

Open the MSI file in InstEd editor
Open Table “Property”
Change ISCHECKFORPRODUCTUPDATES from 1 to 0
Change RebootYesNo from Yes to No
Save and Close

Copy MSI to “\\%UserDomain%\NETLOGON\Flash11”
Open Group Policy Management console

Create new GPO “Deploy_Flash11.X”
Expand “Computer Configuration – Policies – Software Settings”
Right click “Software Installations” and select ‘New – Package’
Browse to “\\%UserDomain%\NETLOGON\Flash11” and select the new MSI
Select deployment method: Assigned – Click OK

Assign GPO “Deploy_Flash11.X” to Test OU
Run “gpupdate /force” – restart on prompt

If install went OK, assign the GPO to Production OUs.