Molecular Modeling software on PCs

[wei-0at0-hermes.chpc.utexas.edu (Tai-Guang Wei)]

 Greetings, everyone, a synthetic organic chemist is looking for a
 molecular modelling software on IBM PCs or comparable machines.
 The software should be user friendly for a user with very little computer
 experience and very little theoretical background.
 The software should not cost too much because the money will come out of
 the person's own pockets.  Of course, it should not be too slow.  No one
 wants to wait for hours to get a response for a command.
 He wants to draw 2-D, 3-D molecular structures, do some energy estimation,
 conformational search, or molecule-molecule interactions(such as protein-ligand
 Anyway, he wants to get some information which an experimental chemist
 wants to know.
 Would someone recommend some software for him?  And how can he get the
 software?
 Any suggestions will be welcome.  Please send your e-mail to
 wei-0at0-hermes.chpc.utexas.edu
 or you can post it on the mailing list if you prefer to do so.
 Thank you very much for your help in advance,
 Tai-Guang Wei