Uninstallation of CSP agent requires a restart.. Try to use the competitive uninstall of SEP (Seprep) then include the uninstallation string of csp agent example below..
[Settings]
ShowGUI=N
ShowMessageBox=N
MessageBoxText=Prepairing your system for Symantec Endpoint Protection 11.0. During this process other antivirus products will be removed.\n\nIf you are prompted please fully remove these products.
AutoRunAfterUILoads=N
AskBeforeRemoval=Y
SilentMSIInstaller=Y
RemoveSymantec=Y
CheckDiskSpace=Y
ResumeAfterReboot=Y
EnableLogging=Y
LogPath=
RunBeforeRemoval="Uninstallation_String_of_CSP_agent"
RunAfterRemoval="your_SEP_installer_package_setup" (Sepsetup.exe)
[UninstallPaths]
SOFTWARE\McAfee\ePolicy Orchestrator\Application Plugins
[ProductNames]
;Programs that must be removed first
Cisco Security Agent
McAfee Agent
McAfee Anti-Spyware
Symantec Crtical System Protection <<<<<<< Add this product name of CSP for the RemoveSymantec=Y option above...
See this article for more info using Seprep utility..
SEPprep competitive product uninstall tool
http://www.symantec.com/business/support/index?page=content&id=TECH148513