How to install macOS Ventura on old unsupported MAC using parallels desktop?

Installing macOS Ventura (version 13.x) on an old, unsupported Mac using Parallels Desktop involves running Ventura as a virtual machine (VM), since Parallels allows you to bypass hardware compatibility restrictions that prevent a direct install on older Macs.

Officially, Ventura supports Macs from 2017 onward (e.g., MacBook Pro 2017, iMac 2017), so if your Mac is older (e.g., pre-2017), this method lets you run Ventura in a VM on your existing macOS host.

Below are detailed steps tailored for this scenario.

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Prerequisites

• Old Unsupported Mac: Any Intel-based Mac running a compatible host macOS (e.g., High Sierra 10.13 to Monterey 12.x). Apple Silicon Macs (M1/M2) have different VM constraints—confirm your Mac is Intel via About This Mac (shows “Intel” in the processor field).
• Parallels Desktop: Version 18 or later (19 recommended as of April 6, 2025). Download from parallels.com (trial or licensed).
• Host macOS: Must support Parallels (e.g., macOS 10.13.6 or later for Parallels 18+).
• Space: 20GB free minimum (64GB+ recommended) for the VM and Ventura installer.
• Ventura Installer: Install macOS Ventura.app or a Ventura .ipsw file (for Parallels on newer hosts).
• Internet: Needed to download Ventura if not pre-obtained.

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Step-by-Step Instructions

1. Verify Your Mac and Install Parallels Desktop

• Check Host macOS:
  • Apple menu > About This Mac. Note your version (e.g., Monterey 12.6).
  • Parallels 18 supports macOS 10.13.6+; Parallels 19 needs 10.15+.
• Install Parallels:
  • Download from parallels.com (choose the version matching your host macOS).
  • Double-click the .dmg, follow prompts to install, and launch Parallels Desktop.
  • If Gatekeeper blocks it (“cannot be opened”), go to System Settings > Privacy & Security > Open Anyway.

2. Obtain the macOS Ventura Installer

Since your Mac is unsupported, you can’t download Ventura directly from the App Store. Use one of these methods:

• Method 1: gibMacOS (Recommended for Unsupported Macs)
  • Open Terminal (Applications > Utilities > Terminal).
  • Install Python 3 (if missing):
    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" brew install python
  • Clone gibMacOS:
    git clone https://github.com/corpnewt/gibMacOS.git cd gibMacOS python3 gibMacOS.command
  • Select “macOS Ventura” (13.x) from the list, download the .pkg, and extract:
    pkgutil --expand-full "macOS Downloads/publicrelease/InstallAssistant.pkg" ~/Desktop/VenturaInstaller mv ~/Desktop/VenturaInstaller/Applications/Install\ macOS\ Ventura.app /Applications/
• Method 2: Use Another Mac
  • On a supported Mac (2017+), download Ventura from the App Store, then transfer Install macOS Ventura.app to your old Mac’s /Applications via USB or network.
• Verify:
  • Check size:
    du -sh /Applications/Install\ macOS\ Ventura.app
  • Should be ~12-13GB.

3. Create a New Virtual Machine in Parallels

• Launch Parallels Desktop:
  • Open from /Applications or Dock.
• Start New VM:
  • Click File > New or the + button in the Control Center.
• Choose Installation Source:
  • Using Installer App (Intel Macs):
  • Select Install Windows, Linux, or macOS from an Image File.
  • Drag Install macOS Ventura.app from /Applications into the window, or click Choose Manually to locate it.
  • Click Continue.
  • Note: If your host is Ventura or later, Parallels might require an .ipsw file instead—see Troubleshooting for details.

4. Configure the VM

• Set VM Details:
  • Name: e.g., “Ventura on Old Mac”.
  • Location: Default is fine (e.g., ~/Parallels).
• Customize Settings (Optional):
  • Click Customize Settings Before Installation.
  • Hardware > CPU & Memory: Allocate 4 CPUs and 8GB RAM (adjust based on your Mac’s total—don’t exceed half).
  • Hard Disk: Default 64GB is fine; increase if needed (e.g., 128GB).
  • Graphics: Set to “Best for Retina” or adjust VRAM if your Mac supports it.
• Save and Proceed:
  • Click Create.

5. Install macOS Ventura

• Boot the VM:
  • Parallels starts the VM and boots from the Ventura installer.
• Install Process:
  • Select your language, click Continue.
  • Choose Install macOS Ventura > Continue.
  • Agree to terms, select the virtual disk (e.g., “Macintosh HD”), and click Install.
• Wait:
  • The VM restarts multiple times (20-40 minutes). Don’t interrupt—watch the progress bar.
• Setup:
  • After installation, complete the macOS setup (language, Apple ID, etc.) to reach the Ventura desktop.

6. Enhance the VM (Optional)

• Install Parallels Tools:
  • Parallels menu > Actions > Install Parallels Tools.
  • Mounts a virtual CD—double-click Install in the VM and follow prompts.
  • Improves integration (e.g., clipboard sharing, dynamic resolution).
• Restart: Reboot the VM after installation.

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Post-Installation

• Test: Open apps in Ventura to confirm functionality.
• Snapshots: Use Actions > Take Snapshot to save states.
• Updates: Update Ventura via System Settings > Software Update in the VM.

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