Greetings, scdda.

I had a similar experience when first I tried to use the desktop app for WinXP. The desktop app ran once, then subsequent attempts to start the app rendered nothing -- it did not show up in the running applications list, was not on the toolbar, etc. I discovered the desktop app had somehow corrupted its program registry within the WinXP registry list. Some components of the desktop app were indeed running, but between the desktop app and WindXP, not everything was in sync. To the casual eye it appeared as though the desktop app just would not start.

Remedy? Not sure there is a permanent remedy from PogoPlug, but here's something you can try to at least get the desktop app back in alignment with WinXP monitors and desktop displays:
1. Open the WinXP task manager (Ctrl/Alt/Del or right-click on the task bar and select the Task Manager).
2. Select the Running Processes tab and request WinXP to "END" execution of the processes that support PogoPlug: PogoPlug.exe, ppfs.exe, ppsync.exe, dokanmnt.exe. It's possible that not all these processes are running, so "END" any and all that are and forget the rest. You can ignore the WinXP alerts that warn of potential issues with stopping running programs. Once this step is complete, close the task manager.
3. Click the Start pane and select the Run option/pane. In the box, type "regedit" and click OK. This will bring up a WinXP file list editor called the Registry Editor. Expand the PogoPlug file to find a subfolder named ppfs. Select the ppfs folder and delete the entire folder. Once deleted, close the Registry Editor.
4. Attempt to restart the PogoPlug desktop ap. It should once again properly register within the WinXP monitoring systems and start properly.

If the desktop app appears to be gone again later, do these steps again. As long as you follow the steps you won't harm the operating system, other running applications, or PogoPlug.

I got my PogoPlug Pro about 8 months ago. I think I've had to do this a couple of times, but only in the first few weeks. Since then the app has worked just fine.

Hope this helps. Bronson.