Two buttons, side by side in the same window. One of them upgrades your Ventoy drive in seconds. The other erases it completely. This page makes sure you never confuse them again.
Almost every story of 'Ventoy deleted all my ISOs' ends the same way: the person clicked Install when they meant Update. Ventoy itself never deletes files during an update - the confusion is purely between the two buttons in Ventoy2Disk. Here is exactly what each one does, when each is correct, and the simple rule that keeps your collection safe.
Install is the from-scratch operation. It repartitions the whole device, creates the data partition and the VTOYEFI boot partition, and formats both. Everything that was on the drive - ISOs, documents, anything - is destroyed in the process. Install is the right choice exactly twice in a drive's life: the first time you create a Ventoy drive, and the day you deliberately decide to start over (see the fresh-install guide in this series). On any other day, it is the most expensive wrong click in the toolbox.
Update assumes Ventoy is already on the device. It rewrites the boot code and refreshes the files inside the small VTOYEFI partition, then stops. The data partition - your ISOs, your ventoy folder with its themes and plugin settings - is left completely alone. The tool even says so in its confirmation message: the data in the first partition will be unchanged. The whole operation takes seconds, because 32 MB is all it ever writes.
Sometimes readers plug in an ordinary pen drive and find Update does nothing useful or reports it cannot proceed. That is correct behaviour, not a bug: there is no Ventoy partition layout to upgrade. Update is a renovator, not a builder - it needs the existing two-partition structure in place. For a fresh drive, back up its contents, use Install once, copy your ISOs across, and from that day forward every upgrade is an Update.
See both buttons explained in the video, including the confirmation message that promises your files stay unchanged.
Watch Full VideoNo. Update needs the existing Ventoy partition layout to upgrade. On a blank or ordinary drive you must use Install once - which formats it - and after that, all future upgrades are done with Update.
Install repartitions and formats the whole device, so the ISO files are erased. Stop using the drive at once; your realistic recovery is restoring the ISOs from copies on your PC or downloading them again. A two-minute backup before updating prevents this completely.
No. Update keeps the existing partition layout exactly as it is and only rewrites the boot code and the small VTOYEFI partition. Your data partition keeps its size, format and contents.