How to Use Your iMac as a Second Monitor for Your PC

Using your iMac as a second monitor for your PC is an excellent way to expand your desktop real estate and increase productivity. With the vibrant Retina display on the iMac providing sharp images, accurate colors, and wide viewing angles, it also makes an ideal external monitor for tasks like photo and video editing.

Compatibility Requirements

However, not all iMacs can be used as external PC displays. To use your iMac in Target Display Mode:

  • The iMac must be a 27-inch model from late 2009 to mid 2014 running macOS High Sierra 10.13 or earlier.
  • You need the proper cable to connect your PC to the iMac’s Thunderbolt or Mini DisplayPort.

Step-by-Step Setup

Follow these steps to use your compatible iMac as a second Windows PC display:

1. Connect the iMac to Your PC

Use a Mini DisplayPort to Mini DisplayPort cable for late 2009 and mid 2010 27-inch iMac models.

For 2011-2014 models, use a Thunderbolt cable to connect to your PC’s Thunderbolt port.

If your PC does not have those ports, you will need an HDMI or DisplayPort to Mini DisplayPort adapter.

2. Enter Target Display Mode

With both computers powered on and connected, press Command-F2 on the iMac keyboard to enter Target Display Mode.

The PC’s screen should now appear on the iMac display.

3. Adjust Display Settings

For best results, set your PC’s display resolution to 2560 x 1440 in Windows settings. This matches the native resolution of most compatible iMac models.

Tips for Smooth Performance

Follow these tips to ensure your iMac functions well as a PC monitor:

  • Use a wired Ethernet connection between both computers for maximum bandwidth and lowest latency.
  • Close resource-intensive apps on the iMac to devote processing power to display duties.
  • Adjust orientation in Windows display settings to match iMac’s aspect ratio.
  • Use original iMac keyboard for guaranteed Command-F2 support.

Alternative Solutions

If your iMac does not meet Target Display Mode requirements, consider:

  • AirPlay from Windows 10 to display to newer iMac models.
  • Third-party apps like Duet Display and Luna Display to wirelessly use iMac as second screen.
  • Buy a separate external monitor for your PC.

So with the proper cables and compatible hardware, using your 27-inch late 2009 to mid 2014 iMac as a stunning high-resolution second PC display is easy. Follow the steps outlined to boost productivity and enjoy the excellent visual experience.

Frequently Asked Questions

What is Target Display Mode?

Target Display Mode is an Apple feature that allows a compatible iMac to be used as an external monitor for another Mac. When the iMac enters Target Display Mode, it becomes a second display for the connected computer.

Can I use any iMac as an external monitor?

No, only certain older 27-inch iMac models (late 2009 to mid 2014) running High Sierra 10.13 or earlier support Target Display Mode. Recent iMacs with Retina 5K displays cannot be used as external monitors.

What cable do I need to use my iMac in Target Display Mode?

  • Late 2009/2010 iMacs require a Mini DisplayPort cable.
  • 2011-2014 iMacs require a Thunderbolt cable.

You may also need HDMI/DisplayPort adapters if your PC lacks those ports.

Why is my iMac not entering Target Display Mode?

If pressing Command-F2 does not trigger Target Display Mode, verify macOS version, cable connections, reboot both devices, or try using the original iMac keyboard. Also log out and back in to the iMac before initiating.

Can I play audio through the iMac speakers while using Target Display Mode?

Yes, you can set the iMac speakers to play audio from the connected PC. In macOS, choose Apple menu > System Preferences > Sound > Output and select the iMac for sound output.