#EDIT
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If you choose standard-size only, any clients that required reduced size content cannot get content updates from the management server. If you choose reduced-size only any clients that require standard-size content cannot get content updates from the management server.
By default both Standard-size and reduced-size content is selected.
To configure Symantec Endpoint Protection Manager to download reduced-size definitions, click Admin > Servers, select the site, and click Edit Site Properties. On the LiveUpdate tab, change the selection for Content Size to Download.
The reduced-size Windows client is actually designed for embedded systems and VDI environments. The reduced-size client is 80% to 90% smaller than the standard-size client because it uses the most recent virus and spyware definitions only. The reduced-size client provides slightly less protection than the standard-size client definitions. Therefore, install and enable all protection technologies to mitigate this small reduction in Virus and Spyware Protection. These protection technologies include the firewall, Download Insight, Intrusion Prevention, and SONAR. Also, use the system lockdown feature to ensure the highest security on reduced-size clients. System lockdown either allows only applications on a specified list (whitelist) or blocks only the applications on a specified list (blacklist).