Solution

1. SEPM Server.
2. Admin TAB.
3. Server TAB.
4. Local site properties.
5. Choose to General setting and check mark Delete Clients that have not connected for (30 for you requirement) days.

.After this setting all client remove automatically in your SEPM database server.

Reference:

SEP 11

http://www.symantec.com/docs/TECH93732

SEP 12.1

http://www.symantec.com/docs/TECH176400

Hi,

You can change the setting to 1 day if it's really required.

By default, inactive client records are deleted after 30 days, if inappropriate for your environment this setting can be changed in the Local Site Properties.

- Open the SEPM Console
- Select "Admin" on the left.
- Select "Servers" at the bottom.
- Right click on "Local Site" and select "Edit Properties".

Here in the "General" tab, you can modify the field for "Delete Clients that have not connected for", in days.

Reference: http://www.symantec.com/docs/TECH93732

Hello,

Is the AD in sync with SEPM? If yes, you could work on the steps provided in the Article below:

Removing duplicate clients from the Symantec Endpoint Protection Manager using the CleanClients tool

http://www.symantec.com/docs/TECH97371

Incase if these machines are imaged machines, you may like to work on the steps provided in this Article:

Configuring Symantec Endpoint Protection 11.x client for deployment as part of a drive image

When we delete a  client from SEPM the client will disappear from the SEPM for the timebeing.Next time when the client hearbeats to the SEPM it will repair.In simple words when the client is deleted from the SEPM it is not deleted from the database

When we delete the entry from the SQL, the client is deleted from the database.

Deletion from SEPM will only reflect in the database if we are purging the database from SEPM ( Delete cleints when the cleints have not connected since X days..option)

1) Open SEPM and click on the Admin tab.

2) Click on Servers.

3) Select the "Local Site" from the list of Servers.

4) Under "Tasks," select Edit Site Properties.

5) Under the "General" tab, there is a check box that says "Delete clients that have not connected for X days." By default this is set to 30. Change the number of days as desired.

6) Click OK.

Atlast, I would suggest you to check the suggestions provided in the Thread below - 

https://www-secure.symantec.com/connect/idea/finding-duplicate-clients-have-same-hardwareid

Hope that helps!!