hi there is a best practices from symantec endpoint protection runing on POS machines for windows emb. and others hope it helps
Symantec Endpoint Protection supports the following common embedded systems on both 32-bit and 64-bit operating systems:
• Windows Embedded Point of Service (WEPOS)
• Windows Embedded POSReady 2009
• Windows Embedded POSReady 7
• Windows XP Embedded (XPe)
• Windows Embedded Standard (WES) 2009, 2011, 2012
• Windows Embedded Standard 7 (Windows 7 Embedded)