Assuming that you installed PyMOL in the standard location:
c:\Program Files\PyMOL\PyMOL
Click Start → Run on the Windows task bar and then type
cmd
You should get a window like this:
Now type the following three lines to access the PyMOL installation directory.
cd \program files cd pymol cd pymol
Your screen should then look something like this:
with the Windows prompt reading something like:
c:\Program Files\PyMOL\PyMOL>
Now type the following command to try to launch PyMOL:
pymolwin.exe +2
You should see some diagnostic output in the window. Assuming that PyMOL does not launch, you will need to copy all of that output and email it to Schrödinger as follows:
This information should assist the PyMOL support team in helping to resolve your problem.