I would try a simple system file check first to make sure everything is nice and clean. Do this from the run line and type sfc /scannow .
Also for a cheap work around if the windows is still active, but everything dissapears most likely explorer.exe got terminited. If you can issue a CTRL-ALT-DLT and get to the task manager you can launch this via a new process. save you a reboot. Just for a more personal note what would you need to right-click on an executable for? Unless you are a programmer that designs them of course
which could be the case...just curious is all.