There are scenarios where the Enterprise Manager will fail to start immediately after installation.
The IntroscopeEnterpriseManager.log will have this message:
The EM failed to start Local Users and Groups realm is misconfigured. Error using new settings forRealm: XMLFileManager CantDeleteFile
The users.xml and realms.xml files have not been updated after installation.
This problem can arise when the Windows User Account Control (UAC) feature is enabled.
It has impact on a number of things, but one relevant thing is that it restricts the activity of programs that are installed into the Program Files folder.
CA APM Support suggests that the Enterprise Manager be installed in a folder other than Program Files, for example, C:\introscope. The installation process should be run as Administrator.
We have found from experience that it is simplest to just disable the UAC feature since the Enterprise Manager will be a dedicated machine.