Project 64 is a popular program that emulates Nintendo 64 games on the computer. As computer processors and video cards have got more powerful, computer emulation has moved from the original Nintendo, to the Super Nintendo and now the Nintendo 64. Project 64 allows the user to play Nintendo 64 games on their computer as computer files (known as ROMs) that you can download on the Internet. Keep in mind that downloading a Nintendo 64 ROM if you do not own the actual cartridge for it is illegal. Playing Nintendo 64 games on your desktop or laptop can take up quite a bit of your machine's resources, however, so there are often issues with games running too slowly.
Stop all open programs. Make sure that Project 64 itself is closed before continuing with this step. If you have Firefox, Google Chrome, or Internet Explorer open, those programs can use quite a bit of your computer's RAM and CPU, especially if you have multiple tabs open. Exit them, along with any other windows you find open on the taskbar at the bottom of your screen.
Go to the Task Manager. Press and hold the Ctrl+Alt+Delete keys at the same time. This will open up the Task Manager, a small window showing which applications are currently running on your computer. Look at the bottom of the task manager for CPU usage. It should be under 10%. If it's not, left click on the "Processes" tab. Search for programs that appear to be using part of the CPU. If you find a background application using an excessive amount of your CPU, simply left-click it, and then left-click on the "End Process" tab in the bottom right corner.
Ensure proper plug-ins are installed to Project 64. The purpose of plug-ins is to make Project 64 as easy as possible to modify. Anyone with programming knowledge can create a plug-in for Project 64. Thus, if one plug-in doesn't work for a particular game, you can simply download and try another one. This greatly enhances the number of playable games on Project 64.
Once inside the Project 64 application, go to the "Options" tab and left click on "Settings" tab in the menu. Ensure that the Video, Audio, and Input plug-ins all have the word "Jabo" in them. Jabo is the creator of some of the best plug-ins available, and should be the first one you try with any newly downloaded ROM game file. If one of them doesn't say "Jabo", do a Google search for "Project 64 Jabo plugin," and it will quickly guide you where to download them.
Turn Project 64 to minimum Graphics settings. Left click on the "Options" tab, and then left-click on the "Configure Graphics Plugin..." tab. This will take you into the video plugin currently used by Project 64. Change the "Windowed Resolution" drop-down tab to "320 x 240" and the "Full Screen Resolution" drop-down tab to "640 x 480 16-bit".
Use advanced speed settings to maximise performance. These settings are labelled "advanced" because they can cause some games to work improperly, but for many others the settings can increases the speed at which games play. Go to the Options tab, and once again select the "Settings" option. Go to the "Options" tab within Settings, and make sure that "Hide Advanced Settings" is not checked.
Additionally, make sure that the "On loading a ROM go to full screen" tab is also unchecked. Left-click on the "OK" button. Go to the "Options" tab once again, and left click on the "Show CPU Usage %" drop-down menu option. This will allow you to see how hard Project 64 is pushing your CPU. If you find that your processor is being used 100% consistently without fast enough speed, it means that your processor is simply not powerful enough to run Project 64. Finally, go to the new "System" tab that has appeared at the top of Project 64. Uncheck the "Limit FPS" drop-down menu option.
If the techniques here do not provide you with a solution, see the References section for the link to the Project 64 forums. Sometimes, a specific Project 64 ROM requires a special Graphics plug-in. This information can also be found on the Project 64 official forums. Generally, a dual core processor with a video card is necessary to run Project 64 at full speed.
It is illegal to download a Project 64 ROM for which you do not actually own a physical copy of for the Nintendo 64. The ROM is meant as a backup, not as a replacement to actually purchase the game.