snmpapi.dll is a DLL relating to the Simple Network Management Protocol (SNMP), which is used to monitor important network equipment on your Local Area Network (LAN). snmpapi.dll should not be disabled/deleted, required for essential applications to work properly like symantec endpoint protection. At times, this file may get corrupted or tampered with by malwares or software installs.
This can resolved your problem error 1053:The service did not respond to the start or control request in timely fashion:
Go to any working SEP client and copy the dll file from C:\Windows\sytem32\snmpapi.dll
then:
Go to client having a problem in SEP (can't start smc service) and paste the snmpapi.dll to C:\Windows\sytem32\snmpapi.dll
after copying the snmpapi.dll... repair the SEP.
You copied snmpapi.dll from working SEP client?
I did these steps and still have the error.
For a full list of Windows error codes:
http://msdn.microsoft.com/en-us/library/ms681381(VS.85).aspx