Before you start installing big (and expensive) tools to trace performance issues, it's a good idea to first have a look at Performance Monitor a/k/a PerfMon. It's an amazing tool that goes far too often unused available freely on every windows machine. Through a lot of different performance counters you can monitor different aspects of your system. To open PerfMon, just go to the Start Menu, choose Run and type perfmon.
If you want to find out how the system is performing, then the following counter give you a good overview of general activity of the system.
- Processor utilization
- Processor\% Processor Time\_Total - how 'loaded' is the CPU at any given time. Don't confuse 100% processor utilization with a slow system though - processor queue length, mentioned above, is much better at determining this.
- Memory utilization
- Process\Working Set\_Total (or per specific process) - this basically shows how much memory is in the working set, or currently allocated RAM.
- Memory\Available MBytes - amount of free RAM available to be used by new processes.
- Disk Utilization
- PhysicalDisk\Bytes/sec\_Total (or per process) - shows the number of bytes per second being written to or read from the disk.
- Network Utilization
- Network Interface\Bytes Total/Sec\nic name - Measures the number of bytes sent or received.
You can find more info about the usage of the performance monitor and some other useful performance counters in this Windows perfmon- top 10 counters post.