If you\'ve already downloaded all 5 .part files and don\'t fancy downloading the entire thing again as an .exe, you could always just open a DOS prompt, go to the directory with the files, and type the following:
copy /b PSV0.20.010.Part1 PSV0.20.010.Part2 PSV0.20.010.Part3 PSV0.20.010.Part4 PSV0.20.010.Part5 PlaneShiftV0.20.010.exe
That should create the .exe file for you, from which you can install the game.