Every data-loss story about silent installation begins with the same misunderstanding: 'first disk' sounds like it means your system disk. It means the first disk the firmware happens to enumerate - which is a hardware detail, not a promise.
Silent mode removes the one screen that protects your data: the one where a human reads the disk list and says yes. This page is the warning label the feature deserves - short, blunt, and worth reading before the option is ever ticked.
When Windows Setup starts, it numbers the disks it can see in the order the machine's firmware and storage controllers present them. That order depends on which ports and slots are populated - a SATA drive on a low port can easily be Disk 0 while the NVMe you think of as 'the main drive' is Disk 1. In a normal install you see the list, with sizes, and choose. Silent mode skips that list entirely and takes the first entry. The changelog phrase 'first detected disk' is precise engineering language, and it does not mean 'the disk you would have picked'.
It plays out like this. A technician boots a silent stick on a PC that has a system SSD and a large data HDD. Setup enumerates the HDD first. With no prompt to interrupt it, partitioning and formatting begin on the data drive within the first minute. By the time anyone glances at the screen, the install is cheerfully progressing - onto the wrong disk, with the old partition table already gone. Data recovery after a partial Windows install onto the same drive is partial at best. Notice that nothing malfunctioned: the bug stories are separate; this disaster is the feature working exactly as described.
Rufus 4.15 'improved the guards for using the silent option' - the warnings around enabling it are clearer. Guards at creation time, however, cannot see the target machine. They cannot know that the PC in front of you has a second drive, or that its Disk 0 held a family's photo archive. The only guard that works at install time is a physically disconnected cable. Treat every in-software warning as a reminder to apply the physical one.
Watch the video for the feature in action, and treat the disconnect rule on this page as part of the feature - not as optional extra caution.
▶️ Watch Full VideoNot from inside the silent flow - no prompt is the entire point of the feature. You control the target the physical way: make sure only one disk is connected, so 'first detected' and 'the disk I mean' are the same disk.
No. Once the machine boots from silent media, setup proceeds through partitioning without a confirmation screen. Any warning exists at media-creation time, in Rufus, in front of whoever made the stick - not at the machine being installed.
The first-disk danger specifically needs a second disk to bite, so a single-disk machine removes this particular risk. The general new-feature caution still applies: use a current Rufus build, and do one watched install before trusting any unattended flow.