Google is your friend........
Let's say that Explorer opens at C:\ and you want D:\ to be open on startup. Find the shortcut in the Windows\Start Menu and change the properties from:
C:\WINDOWS\EXPLORER.EXE /n,/e,C:
to
C:\WINDOWS\EXPLORER.EXE /n,/e,D:
To open in My Computer, use:
C:\WINDOWS\EXPLORER.EXE /n, /e, ::{20D04FE0-3AEA-1069-A2D8-08002B30309D}
Note the double colon.
To open to "My Documents" folder, use:
C:\Windows\Explorer.exe /n, /e, ::{450d8fba-ad25-11d0-98a8-0800361b1103}
Note the double colon.
Windows Explorer Command-Line Switches
explorer [/n] [/e][,/root,object][[,/select],subobject]
Parameters
/n
Always open a new window (even if the specified folder is already open).
/e
Use Windows Explorer view. The default is Open view.
/root,object
Specify the object in the normal name space that will be used as the
root of this Windows Explorer Folder. The default is to just use the
normal name space root (the desktop).
subobject
Specify the folder to receive the initial focus unless /select is used.
The default is the root.
/select
Specifies that the parent folder is opened and the specified object is
selected.
Windows Explorer Examples
To open a window rooted at \\myserver so you can easily
browse the whole server, but nothing else:
explorer /e,/root,\\myserver
To open a folder window on C:\WINDOWS (or make an open window active) and
select CALC.EXE, use:
explorer /select,c:\windows\calc.exe