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You want to change the default location for Windows 7's version of Windows Explorer, and have it default to opening C:\
The simplest way to open the Windows 7 version of Explorer is to click the folder icon in the task bar. This opens an Explorer window in the Libraries location, which gives you one-click access to your documents, pictures, videos, and music.
For most people, the Libraries location makes a reasonable place to start exploring, but you may not be like most people. Depending on your work habits, My Computer, My Documents, DropBox, or some other alternative may make more sense.
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The easiest solution to opening Explorer where you want it is to pin your location to the Windows Explorer icon on the taskbar. To do this, open Windows Explorer. Find your desired location in the left pane, and drag it to the Windows Explorer icon on the taskbar. When you let go, it will be "pinned" to the Explorer menu.
This won't actually change the default. When you simply click the Windows Explorer icon, you'll still get Libraries. But if you right-click that icon, you'll find your desired location on the resulting menu.
You can also drag the location to the desktop or the Start menu and open your preferred location from there.
But with a little more work, you can change the default:
Right-click the Windows Explorer icon on the taskbar, then, on the resulting menu, right-click Windows Explorer. Select Properties.
Note the Target field in the resulting dialog box's Shortcut tab. It will probably say %windir%\explorer.exe. To change the default, add a space, then a path, to the end of that statement. For instance, to make Windows Explorer default to opening your C drive, change the Target to to %windir%\explorer.exe c:\. (That period is the end of my sentence, not part of what you type.)
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Unfortunately, not all the paths are that obvious. If you prefer My Computer as your default, use the path shell:MyComputerFolder. For My Documents, use ::{450D8FBA-AD25-11D0-98A8-0800361B1103}.
Below are some popular folders that you might want to open instead of the default.
Warning
By design in Windows, these shortcuts will open a new window in a new process (explorer.exe) each time you use the shortcut. When you close the opened window from the shortcut, the extra explorer.exe process will close with it as well a few moments afterwards.
♦ Windows Explorer (default) (opens to Libraries)
%windir%\explorer.exe
♦ Computer
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}
or
%windir%\explorer.exe shell:MyComputerFolder
♦ My Documents
%windir%\explorer.exe /n,::{450D8FBA-AD25-11D0-98A8-0800361B1103}
♦ Documents Library
%UserProfile%\AppData\Roaming\Microsoft\Windows\Libraries\Documents.library-ms
♦ Downloads
%UserProfile%\Downloads
♦ Recycle Bin
%windir%\explorer.exe /n,::{645FF040-5081-101B-9F08-00AA002F954E
♦ Network Neighborhood
%windir%\explorer.exe /n,::{208D2C60-3AEA-1069-A2D7-08002B30309D}
♦ Default Web Browser (ex: Internet Explorer)
%windir%\explorer.exe /n,::{871C5380-42A0-1069-A2EA-08002B30309D}
♦ Computer Search Results Folder
%windir%\explorer.exe /n,::{1F4DE370-D627-11D1-BA4F-00A0C91EEDBA}
♦ Network Search Results Folder
%windir%\explorer.exe /n,::{E17D4FC0-5564-11D1-83F2-00A0C90DC849}
♦ Web Folders
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{BDEADF00-C265-11D0-BCED-00A0C90AB50F}
♦ Control Panel
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}
♦ Printers and Faxes
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{2227A280-3AEA-1069-A2DE-08002B30309D}
♦ Scanners and Cameras
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{E211B736-43FD-11D1-9EFB-0000F8757FCD}
♦ Fonts
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{D20EA4E1-3957-11d2-A40B-0C5020524152}
♦ Network Connections or My Network Place
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{7007ACC7-3202-11D1-AAD2-00805FC1270E}
♦ Administrative Tools
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{D20EA4E1-3957-11d2-A40B-0C5020524153}
♦ Tasks Scheduler
%windir%\explorer.exe /n,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\ ::{21EC2020-3AEA-1069-A2DD-08002B30309D}\::{D6277990-4C6A-11CF-8D87-00AA0060F5BF}
♦ User Profile (personal) Folder
%windir%\explorer.exe shell:Profile
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source:pcworld & special thanks to Shawn@sevenforums