Have you done all of the Windows Updates?
If not, you must do all of the Updates from
http://windowsupdate.microsoft.com
Click on Custom and then make sure that you select everything under Software on the Left hand side.
You might have to do this up to 8-10 times.
Do you see the Plextor drive in your Microstudio Software? If so it is recognizing the drive and the drivers are working. If not, then Uninstall the Microstudio and Reinstall it. This should then allow your drive to show.
Let me know what happens once you do this.