You might have been told This PC doesn't currently meet Windows 11 system requirements because your VM doesn't have TPM 2.0 and Secure Boot. This guide is for you.
Tested in VMware Fusion 12.1.2 on a macOS Big Sur 11.6 host.
Note: this guide is for running x86-64 Windows 11 in a VM on an x86-64 Mac host machine. M1 Macs need Parallels, to virtualize ARM Windows 11 on M1-based Macs (even if Microsoft officially doesn't want this).
Skip this step if you originally created the VM using the UEFI firmware type or have already made the switch.
Originally here I was going to capture the steps to convert an MBR-partitioned Windows system to GPT, but, it's non-trivial and a waste of time if you just want a Windows 11 system to test on. Create a new VM and install fresh Windows 10 on it. If you have an existing Windows 10 system, you can create an up-to-date ISO using https://www.microsoft.com/en-us/software-download/windows10 the Windows 10 Media Creation tool. Make an ISO with this. Move the ISO out to the host Mac. Then back in the VM settings, choose CD/DVD and check the box for Connect CD/DVD Drive, providing it the Windows install ISO. Then also in the VM settings, set the Startup Disk to be the CD. Plus, if you start from scratch you can save 30 minutes on enabling encryption.
Shut down the VM, and open the VM's Settings menu within VMware Fusion. Check Compatibility and make sure this virtual machine is using virtual hardware version 13 or later. If not, upgrade.
Then find Advanced, and scroll to Firmware type and change the Value from Legacy BIOS to UEFI. Additional settings should appear: also check the boxes for Enable UEFI Secure Boot and Enable VBS (Virtualization Based Security).
Shut down the VM, and open the VM's Settings menu within VMware Fusion. Click the combination lock icon (Encryption), and check the box for Enable Encryption. If this is not a new blank VM, expect this to take around 20-25 minutes for a 200GB virtual disk, even on a 10th generation Intel Core i7 with 32GB RAM.
Shut down the VM, and open the VM's Settings menu within VMware Fusion.
Click on the Add Device… button in the top right of the Settings window. Choose a device to add… and choose Trusted Platform Module.
Start with a Windows 10 VM. Snapshot now, or make a copy of it.
From within the VM: Open the Start Menu, and search Check for Updates within the Settings app. See the bottom left: click Windows Insider Program and complete the steps to link your Microsoft account and enroll in a "channel" of pre-release updates. I chose "Beta". You may also have to enable additional diagnostics and activity spying in the Windows settings, to be allowed to enroll.
Restart if prompted, and return to the Settings page for updates.
After updates are downloaded, you'll restart again, and it will apply them, turning the Windows 10 VM into Windows 11.