It is not possible to use the original LucasArts installer on the Jedi Knight and Mysteries of the Sith Discs when using 64-Bit systems. There are two different installers available for installing these games. You must have the game installation disc mounted on your computer to use with this installer.


STEP 1 - Download and Run the Jedi Knight: Dark Forces 2 64-Bit Installer



FIGURE 1 - Click Next to proceed.



FIGURE 2 - Click Next to proceed.



FIGURE 3 - Click Next to proceed.



FIGURE 4 - Make sure "Create a desktop icon" and optionally "Install cutscene videos (requires Disc 2)" is checked.



FIGURE 5 - Jedi Knight will begin to install.



FIGURE 6 - If you chose to Install Cutscene Videos during setup, you will recieve this message and you need to mount the jkdisc2.iso so that the installer knows where to find disc 2.



FIGURE 7 - The setup will complete.



FIGURE 8 - Uncheck "Run Star Wars Jedi Jnight" and Click Finish. 
You need to make sure your Launch shortcut is set to launch in Windowed Mode otherwise you may have issues starting Jedi Knight.
Refer to the guide How to Launch Jedi Knight in Windowed Menu Mode with -windowgui

STEP 1 - Download and Run the Mysteries of the Sith 64-Bit Installer



FIGURE 1 - First setup page. Click Next.



FIGURE 2 - Click Next.



FIGURE 3 - Additional tasks page. Check "Create a desktop icon" and "Install cutscene videos".



FIGURE 4 - Ready to install. Click Install.



FIGURE 5 - Progress bar. Setup will begin.



FIGURE 6 - Setup complete. Uncheck "Run Star Wars Mysteries of the Sith".

You need to make sure your Launch shortcut is set to launch in Windowed Mode otherwise you may have issues starting Jedi Knight.
Refer to the guide How to Launch Mysteries of the Sith in Windowed Menu Mode with -windowgui.