How can I tell which "explorer.exe" process is the main one?

Window title based approach

@techie007 suggested killing the explorer.exe with window title N/A.

Command

for /f "tokens=2,10" %%p in ('tasklist /nh /v /fi "imagename eq explorer.exe"') do if "%%q"=="N/A" taskkill /f /pid %%p

How it works

• tasklist /nh /v /fi "imagename eq explorer.exe" verbosely lists all processes with image name explorer.exe.

• for /f "tokens=2,10" %%p in ('COMMAND1') do COMMAND2

  executes COMMAND1. For each line of output, it sets the variables %%p and %%q to the second and tenth "token" (delimited by space) and executes COMMAND2.

  In the case of taskkill /v, %%p now holds the PID and %%q the (beginning of) the window title.

• if "%%q"=="N/A" taskkill /f /pid %%p checks if the window title is N/A.

  If so, it terminates the process with taskkill.

Memory usage based approach

@Syntech pointed out that this is unreliable for Windows Explorer, but in programs, the main process has always the highest memory usage.

Command

for /f "tokens=2" %%p in ('tasklist /nh /fi "imagename eq explorer.exe" ^| sort /+65') do @set explorerpid=%%p
taskkill /f /pid %explorerpid%

How it works

• tasklist /nh /fi "imagename eq explorer.exe" lists all processes with image name explorer.exe.

• sort /+65 sorts the previous output starting with the 65th character (where mem usage begins).

• for /f "tokens=2" %%p in ('COMMAND') do @set explorerpid=%%p sets explorerpid to the second (tokens=2) input – delimited by spaces – of each line of the output of COMMAND, which is the corresponding PID.

• Since tasklist's ouput has been sorted, explorerpid holds the claimed PID, and taskkill terminates the process.

Perhaps you can tell Explorer to show the path in the title bar, and then use the WINDOWTITLE filter to kill it based on that?

• Open Explorer
• Press Alt
• Click on "Tools (menu item)"
• Click on "Folder options... (menu item)"
• Click on "View (page tab)" in "Folder Options"
• Click to select "Display the full path in the title bar (Classic theme only)" in "Folder Options"
• Click on "Apply" -> "OK"

The path won't show in Explorer's title bar with the 'non-classic' themes, but it is (now) there; it's just not visible.

taskkill /F /FI "WINDOWTITLE eq C:\PathToThing\RunningInExplorer\ToRestart*"

You may need to switch to a classic theme temporarily to determine what the path/title is for the Explorer instance you want to restart.

Not 100% fool-proof, but any Explorer windows that don't have that (partial) path in the title would be safe at least. :)

edit:

Since you want to grab the one with title "N/A", you'll probably have to use a batch file so that you can tokenize the results of a TASKLIST adn tehn use those token results to use TASKKIL to kill by PID.

I found an answer over to StackOverflow.com that addresses this:

From question Taskkill an untitled process? is this answer which includes this example batch file:

@echo off
SETLOCAL enabledelayedexpansion
for /f "tokens=*" %%a in ('TASKLIST /V') do (
  set s=%%a
  set p=!s:~27,5!
  set t=!s:~152,3!
  if '!t!'=='N/A' ECHO TASKKILL /PID !p! /T
)

You'll want to change the 'TASKLIST /V' command to be more specific to Explorer.exe and such, but it should give yo a good starting point.

Kill the process with the lowest PID (Process ID). It would have been started first, as processes get numbered sequentially.