Instructions:

Plug in the programmer.

When the P/S short-circuit cap is closed, enter the "CH341-USB programming driver_support WIN7" folder and run "CH341PAR.EXE" to install it. You can also enter the device manager and install it manually.
When the P/S short-circuit cap is disconnected, enter the "CH341 serial TTL drive_support WIN7" folder and run "CH341SER.EXE" to install it. You can also enter the device manager and install it manually.

If your system is 64-bit VISTA or 64-bit WIN 7, you need to press F8 to select "Disable Digital Signature Mode" when booting the system.
When installing the driver, the dialog box that pops up to alert should select "Continue to install".

If the installation fails, you can go to the device manager for manual installation.