Monitoring a Database on Windows

Tools
Oracle Counters for Windows Performance Monitor
Monitor database objects, such as CPU usage, buffer cache, or a background process.
Start > Programs > Oracle - HOME_NAME > Configuration and Migration Tools > Oracle Counters for Windows Performance Monitor

Event Viewer
Monitor database events
Start > Programs > Administrative Tools > Event Viewer

Trace Files
Record occurrences and exceptions of database operations
BACKGROUND_DUMP_DEST

Alert Files
Record important information about error messages and exceptions during database operations
BACKGROUND_DUMP_DEST

Oracle Enterprise Manager
Monitor and tune using tools with real-time graphical performance information

Oracle Administration Assistant for Windows
View information on or terminate any Oracle thread.
Start > Programs > Oracle - HOME_NAME > Configuration and Migration Tools > Administration Assistant for Windows