Dear Support,

i generated a sep package, when the pc installed the package it will go to the default group. but i manually created several groups for easy management, and manually move pc to related group according our defined rules like IP address. now i have a question, there is a pc named PC1, and i move PC1 to the group Group1, and someday, i reinstall the sep client on PC1 due to some reason, or i reinstall windows for the PC1, when i reinstall sep for PC1, will it automatically go to the default group, or the group Group1 ? thanks 

It will go Default group.

it will go to group1

whenever you create a package , there is a  preferred group mentioned for the package, meaning after install the client would report to that group.if the group does not exist ( if u delete before install) then the client would report to default group

Since you already had SEP client installed. it would check for that group. if you want to clear all the details of group and report to new group then you need to select this option during install

How to create a client install setting to remove previous logs, policies and reset the client-server communication settings.

http://www.symantec.com/business/support/index?page=content&id=TECH93617

thanks James007 and Rafeeq, I tried, and it was proved it will go to Group1, so Rafeeq is right. 

but i have another question, why i can see duplicated PC names in the group ? how it come ?

You can remove inactive client for sepm

How to configure the number of days after which inactive clients will be deleted from the SEPM database.

Dear James007,

thanks for your tips, i know how to remove the inactive clients, i want to know why it has duplicated items ?

duplicate clients show up because of duplicate hardware id.

if its just this PC, then delete it from the console.

if you install from images, they all contain same hardware id , so one client will show up and others will showup offline

  here is the link for more details

http://www.symantec.com/business/support/index?page=content&id=TECH97626

If you will uninstall sep client or reinstall OS so sep client not remove automatic.you need to remove that old sep client entry.

Duplicate Hardware IDs result in only one client showing up in the Symantec Endpoint Protection Manager for multiple systems

http://www.symantec.com/docs/TECH97626

https://www-secure.symantec.com/connect/forums/avoid-problem-duplicate-hardware-ids

Thanks James007 and Rafeeq, you help me out. 

HTH, have a good weekend.