Migration Assistant
I have already started the transfer between a PC and the new iMac over Wi-Fi. 27 hours left! Is it too late to use a USB connection or some other method?
iMac (M1, 2021)
Yes you can stop the migration. Chances are it has failed anyhow, NEVER EVER use Wi-Fi to migrate, the failure rate is close to 100%. When migrating from a PC, when I did it I simply move my important files from my PC to an External Hard Disk and then copied them from the PC to the Mac. When copying them it's really simple, for example if you are copying photos just select all the photos and drag them to the Photos app icon in the Dock and all your photos are imported into Photos!
When migrating to a new Mac from an old Mac the process is much easier. You can simply connect the old Mac's Time Machine External Hard Disk to the new Mac on initial startup and the new Mac can migrate the old Macs data, settings and apps to the new machine.
