Change the folder that Windows Explorer starts at

"%windir%\explorer.exe /n, /e, /select, C:\

The above selects the C:\ drive, but it does not open it, effectively making Computer your selected folder on the left pane.

Enjoy :)

It is not meant to ignore other answers that already addressed it. My vote goes to them. But I prefer human-readable stuff to abstract things like ::{20D04FE0-3AEA-1069-A2D8-08002B30309D}."