I can not change the SD Card drive letter
There are many ways to start the SDExplorer. By far the easiest is via the Autoplay support in Windows XP. When you insert an SD Card with KN7000 songs on it into any drive, the Autoplay window will offer SDExplorer as one of its options. Select it and SDExplorer will open that SD Card.
SDExplorer adds an entry to the Windows Explorer right click menu for any drive or folder that contains a KN7000 file structure. In the Windows Explorer, select your SD Card drive or folder, open the right mouse click menu and select Explore KN7000 SD Card. SDExplorer will open that drive or folder.
SDExplorer does not know the drive letter of your SD Card, it can open any folder that contains KN7000 files. It is like the Windows Explorer that doesn't offer a direct shortcut to your C: drive, but you can make one yourself. Just to get you started, the KN7000 SDExplorer asks your SD Card drive letter during installation and adds shortcuts for this SD Card to your desktop and Start Menu. You can simply add more shortcuts to other drives or folders in the same way. Create a new shortcut, for instance on your desktop: right click on your desktop and choose New -> Shortcut. As the location for which you make the shortcut, enter the path to SDExplorer.exe in the folder where you installed it and your chosen drive letter or folder like this:
"C:\Program Files\KN7000\SDExplorer\SDExplorer.exe" K:
On Windows 8.1:
"C:\Program Files (x86)\KN7000\SDExplorer\SDExplorer.exe" K:
Adjust the letter K to be your drive letter.
If you installed in the default place and K: is the letter of the additional drive you want to create the shortcut for. Now choose Next and enter the label for your new shortcut. Now Finish and you should be able to open the new drive from the shortcut on your desktop. So if during installation you entered the wrong drive letter, you can remove the shortcut from the desktop and create a news one according to the procedure above.