In the v4 Beta Users Guide I read:

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I have an old version of EMET installed. How do I upgrade to EMET 4.0 Beta?
It is recommended that you first uninstall the old version of EMET via Windows Control Panel, and then manually delete the HKLM\Software\Microsoft\EMET and HKLM\Software\Policies\Microsoft\EMET keys prior to running the EMET 4.0 Beta installer.
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Hi ManServ,

It is very likely that upgrading from v3 to v4 will be a supported upgrade path. If not, any incompatibilities between release versions will be mentioned in the blog post that announces the new version.

This aspect of deploying EMET was mentioned for EMET v3 and v3.5 Tech Preview:

http://blogs.technet.com/b/srd/archive/2012/05/15/introducing-emet-v3.aspx

http://blogs.technet.com/b/srd/archive/2012/07/24/emet-3-5-tech-preview-leverages-security-mitigations-from-the-bluehat-prize.aspx

In the first link above it was mentioned that upgrading from v2.1 to v3.0 was supported and would work as expected with no need to uninstall.

However since v3.5 was a Tech Preview upgrading from v3.0 to v3.5 Tech Preview required an uninstall (mentioned in the 2nd link above) but would still use any applications rules that were in place for v3.0.

From reading past User Guides the deletion of the following registry keys is usually only necessary when upgrading from a beta version of EMET to the released version e.g. section 7.4 General Questions on Page 32 of the EMET v3 Users Guide.

Upgrading to v2.1 from EMET v1.0.2 was also mentioned in section 6.1: EMET 1.0.2 Questions on Page 20 of the EMET v2.1 Users Guide.

Presumably this provides a clean installation of the release version and removes any registry keys that may have been used for debugging purposes. In addition, default registry settings may change from a beta to a release version.

As you are aware, due to the new features within EMET v4.0 Beta, there are more registry values than the older v3:

EMET v4.0 Beta:

Direct Link to Image:

http://i742.photobucket.com/albums/xx69/Jimboc/Microsoft/EMET_4_Beta_Reg_Settings.png

EMET v3:

Direct Link to Image:

http://i742.photobucket.com/albums/xx69/Jimboc/Microsoft/EMET_3_Registry_Settings.png

The above screenshots show the following registry key:

HKLM\Software\Microsoft\EMET

I hope this helps. Thank you.

Hi everyone,

The final version of EMET 4.0 is now available. Full details (including how to upgrade from previous versions) are provided in the following blog post:

http://blogs.technet.com/b/srd/archive/2013/06/17/emet-4-0-now-available-for-download.aspx

Thank you.

It mentions that v3 to v4 is a direct upgrade and you will be prompted for migrating existing settings.

Is there some flags to automate this for enterprise deployment?

Additionally, where can we get the admx files for upgrading a network stored group policy schema?

Hi Network Janitor,

Please see pages 28 to 31 (Section 3 up to and including section 3.2) of the EMET 4.0 Users Guide for advice on deploying EMET in an enterprise environment.

In addition, there is an admx file included in the following folder once EMET 4.0 is installed:

64 bit Windows:

C:\Program Files (x86)\EMET 4.0\Deployment\Group Policy Files

32 bit Windows 

C:\Program Files\EMET 4.0\Deployment\Group Policy Files

I hope this helps. Thank you.

Thanks JamesC_836,

I forgot where I found these files before, thanks for the reminder :)