HI,

Supported upgrade paths to Symantec Endpoint Protection Manager 12.1 from Symantec Endpoint Protection Manager 11.x

http://www.symantec.com/business/support/index?page=content&id=TECH192779

Upgrade clients to SEP 12.1 by Auto upgrade feature

http://www.symantec.com/connect/articles/upgrade-clients-sep-121-auto-upgrade-feature

If you want to move SEPM server 2003 to 2012 check this artical

https://www-secure.symantec.com/connect/articles/hot-move-sepm-one-server-another-server

SEP 12 RU 2 will support 2012 server. SEP 11 will not.

First upgrade the SEP 12 RU2 , then move the SEPM to new server having windows 2012 server.

Hello,

I agree with Pete.

SEP 12.1 RU2 is the only product which supports Server 2012.

SEP 11.0.7300 is not supporting Server 2012 / Windows 8.

So, your plan of Action would be as follows - 

1) Upgrade / Migrate the SEP 11.0.5002 to SEP 12.1 RU2 (servers and clients).

Check this Article:

Best practices for upgrading to Symantec Endpoint Protection 12.1.2

http://www.symantec.com/docs/TECH163700

2) Once migrated, take a back up of the SEPM server following the Disaster Recovery of SEP 12.1 RU2

Check this Article:

Symantec Endpoint Protection 12.1: Best Practices for Disaster Recovery with the Symantec Endpoint Protection Manager

http://www.symantec.com/docs/TECH160736

3) Migrate the Server 2003 to Server 2012

4) Follow the Article in Step 2 to Restore the SEPM .

Hope that helps!!

You can upgrade right to 12.1.2. Check the articles above for further guidance.

Hi,

Q. I'm looking at upgrading our Endpoing protection to the latest version, however I'm a bit confused about the upgrade path? Also is there anything I need to do to the cliens or will they auto update with the new install?

-->  Please check supported upgrade path for both i.e SEPM & SEP clients, go through these articles.

Supported upgrade paths to Symantec Endpoint Protection Manager 12.1 from Symantec Endpoint Protection Manager 11.x

http://www.symantec.com/business/support/index?page=content&id=TECH192779

Supported upgrade paths for the Symantec Endpoint Protection client

http://www.symantec.com/docs/HOWTO81070

To upgrade clients you can use Auto upgrade feature.

http://www.symantec.com/connect/articles/upgrade-clients-sep-121-auto-upgrade-feature

Q. Also we are looking at migrating from Windows 2003 -> 2012 at the same time. Is it advisable to do it all at once, or upgrade SEM first then install SEM on the new server and switch over?

--> This question can be answered with best possible solution if you could provide following details

1) Total number of clients

2) Total number of SEPM's