I have installed a harbor breeze ceiling fan for a friend. The light works fine but the fan is not working at all. Any ideas what I might do to correct this??

If a separate switch/control, they could be bad,
Check Direction switch and speed switch.
Does it hum? Will spinning help get motor turning?
Then, if capable test for power under canopy if able to do safely

Is it a remote fan?

See:

General ceiling fan troubleshooting and help FAQ- Ceiling Fans N More

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More