Hi,
Q. I am currently running SEPM 12.1.1101 and SEP 12.1.1101, SEP 11.0.6200 clients. (SEP 11.0.6200 for Win 2000 only) My question is if I upgrade SEPM to the latest version will SEP 12.1.1101 and SEP 11.0.6200 client continue to work?
--> It will work without any issue. But it's recommended to have SEPM and SEP clients on the same version. Upgrade to the latest available release of SEP to enjoy many other enhancements and improvements.
Q. Also can I upgrade current SEP 12.1.4 machines by installing SEP 12.1.4 to machines right on top of it or do I need to uninstall agent prior to installation? Thanks
--> I think this question is not correct. You mentioned SEP 12.1.4 at both the time. However you can upgrade from any SEP client version to 12.1 RU4 without uninstall and reinstall.
Firts upgrade SEPM can refer the following article:
https://www-secure.symantec.com/connect/articles/sep-11x-sep-121-upgrade-process-graphical-overview
After successful SEPM upgrade plan for SEP client upgrade.
Upgrade clients to SEP 12.1 by Auto upgrade feature
https://www-secure.symantec.com/connect/articles/sepm-121-auto-upgrade
Note: SEP 12.1 employs a side-by-side, replace on reboot installation strategy. Side-by-side means that new files are written to a new folder, referred to as a silo, isolated from the existing operational folder. Because the two versions are separated from each other, during a migration the older software is left running unchanged until the next reboot.
The primary benefit of side-by-side installation and replace on reboot is that the system continues to be protected by the existing software until the new version is in operation after the reboot.
This technique enables you to change the normal portion of the installation path during a migration, when applicable.