Is there a way to set up a default folder for Windows Explorer?

Edit the following registry subkey:

HKEY_CLASSES_ROOT\Folder\shell\explore\ddeexec

If you change this subkey's default value to [ExploreFolder("yourNetworkDrive", yourNetworkDrive, %S)], you force Windows Explorer to start at the drive you specify.

Replace yourNetworkDrive with the drive you want. If the drive is mapped as S:, the string would be [ExploreFolder("S:\", S:\, %S)].

To present a single-pane Windows Explorer view, you can change ExploreFolder to ViewFolder.

To change the default setting so that all top–level drives and folders are shown, follow these steps:

1. Click Start, point to Programs, then Accessories, then right–click Windows Explorer, and click Properties.
2. Under Target field, which reads %SystemRoot%\explorer.exe, add to make the line read %SystemRoot%\explorer.exe /n, /e, /select, C:\
3. Click OK.

source

I actually use a utility called WinKey to do something similar to this, without rerouting Win+E. I'm sure AutoHotkey could do the same thing. In fact, having said that, I think I just made some work for myself. :)

In WinKey (or soon, in AutoHotkey) I mapped Win+W to open a Windows Explorer window rooted at my standard "workspace" (thus, +W). This way I retain the standard Win+E, which I also use extensively, and right beside it is the hotkey to open my workspace.

OK, work's done. Here's a simple AutoHotkey script I'm now using for Win+w to open my workspace:

#w:: ;; Win+w
{
 Run C:\WINDOWS\explorer.exe /n`, /root`, C:\workspace\
}
return

The command's commas are escaped with a backquote. Replace C:\workspace\ with whatever folder you want to view. Replace "/root" with "/select" if you want two-pane instead of single-pane.

Another example of autohotkey script here

I used Windows Explorer settings:

Open any folder, click on view settings and in General window change "Open File Explorer to".

It contains only two settings in my case, but it got me rid of quick access.