Windows Enterprise Client Boot and Logon Optimization – Part 14, Boot Phase – Explorer Initialization

This post continues the series that started here.

In the last post, I mentioned that the Winlogon phase ended as it launched Explorer. With this, the system enters the Explorer Initialization phase.


As we’ll see, Explorer Initialization is a fairly simply phase with a short list of activities.

Boot Phase Explorer Initialization – Phase Activity

The list of activities for this phase are –

  • Explorer.exe starts
  • Desktop Window Manager starts
  • The desktop is displayed for the first time
  • Auto-start (Run-keys) applications are launched

Boot Phase Explorer Initialization – Measurement

As has been the case for the other phases I’ve discussed, the summary XML generated with xperf.exe provides phase timing as ExplorerInit


Windows Performance Analyzer (WPA) shows the phase duration in the Regions of Interest graph as Boot-ExplorerInit:


Boot Phase Explorer Initialization – Potential Issues

Explorer Initialization is usually a quick phase, taking only a couple of seconds but it may become longer with high disk contention. As services, antivirus, and auto-start applications compete, the system disk I/O becomes important.

Additionally, Explorer Initialization is a CPU intensive phase. CPU competition with other processes may delay the user experience. Run and RunOnce registry keys may introduce some of these competing processes.

Boot Phase Explorer Initialization – Remediation

As I’ve just mentioned, CPU and Disk utilization are an important consideration during this phase. After selecting and zooming to the Boot-ExplorerInit: phase in WPA, you should review these first as discussed in Post 9.

Regions of Interest provides some great insight into sub-activities that occur during initialization of the shell. Simply expand Boot-ExplorerInit: in the Regions of Interest left-hand pane –


You may also use the Generic Events table to interrogate applications launched from registry run keys (again, column ordering is important) –


Ultimately your goal will be to lighten the load on CPU and Disk. Identify non-essential processes that run during this phase and either remove them or consider launching them as delayed scheduled tasks (screenshot from Task Scheduler) –


The AutoRuns tool is valuable for disabling or removing auto-start applications.


Explorer Initialization is a fairly simple phase where you main goal is to reduce CPU and Disk utilization so that the shell can be started as soon as possible.

Next Up

Boot Phase – Post Boot