Set folder browser dialog start location

Just set the SelectedPath property before calling ShowDialog.

fdbLocation.SelectedPath = myFolder;

To set the directory selected path and the retrieve the new directory:

dlgBrowseForLogDirectory.SelectedPath = m_LogDirectory;
if (dlgBrowseForLogDirectory.ShowDialog() == DialogResult.OK)
{
     txtLogDirectory.Text = dlgBrowseForLogDirectory.SelectedPath;
}

Set the SelectedPath property before you call ShowDialog ...

folderBrowserDialog1.SelectedPath = @"c:\temp\";
folderBrowserDialog1.ShowDialog();

Will start them at C:\Temp

fldrDialog.SelectedPath = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory)

"If the SelectedPath property is set before showing the dialog box, the folder with this path will be the selected folder, as long as SelectedPath is set to an absolute path that is a subfolder of RootFolder (or more accurately, points to a subfolder of the shell namespace represented by RootFolder)."

MSDN - SelectedPath

"The GetFolderPath method returns the locations associated with this enumeration. The locations of these folders can have different values on different operating systems, the user can change some of the locations, and the locations are localized."

Re: Desktop vs DesktopDirectory

Desktop

"The logical Desktop rather than the physical file system location."

DesktopDirectory:

"The directory used to physically store file objects on the desktop. Do not confuse this directory with the desktop folder itself, which is a virtual folder."

MSDN - Special Folder Enum

MSDN - GetFolderPath