Web Applications, Security & Maintenance: The Personal Trainer for IIS 7.0 & IIS 7.5

Consider changing the maximum worker processes for application pools.

Consider changing application pool queue length

Counters for physical and logical disks might need to be enabled before they’re available. To enable these objects, run the following commands at a command prompt:
Diskperf -yd for physical disks
Diskperf -yv for logical disks

When you use performance logging, you’ll need to be at least a member of the Performance Log Users group in the domain or the local computer to work with performance logs on remote computers.

you can use Performance Monitor to configure alerts that send messages when certain events occur, such as when an automatic IIS restart is triggered.
The Reliability And Performance Monitor console also includes Reliability Monitor, shown in Figure 7-10. Reliability Monitor tracks changes to the server and compares them to changes in system stability. In this way, you can see a graphical representation of the relationship between changes in the system configuration and changes in system stability. By recording software installation, software removal, application failures, hardware failures, Windows failures, and key events regarding the configuration of the server, you can see a timeline of changes in both the server and its reliability, and then you can use this information to pinpoint changes that are causing problems with stability.

Windows Reliability Monitor Tracks changes to the system and compares them to changes in system stability, thus giving you a graphical representation of the relationship between changes in the system configuration and changes in system stability.