We are aware that a set of users are reporting a slow or seemingly-stuck upgrade experience when attempting to upgrade to Windows 10 or update between versions of Windows 10. The upgrade process usually takes 90 minutes or less to complete, but there
is a very small subset of PCs, usually older or slower devices, where the upgrade process can take longer than typical. This situation is not related to a specific upgrade tool and has been shown to happen with Windows 10 Upgrade Assistant, Media Creation
Tool, USB media, and ISO media.
In these cases, even if the progress percentage appears stuck, the upgrade is still running. An error message should be displayed in case of actual failure. Cancelling and trying alternate methods is unlikely to improve the experience and will reset
any upgrade progress made.
We recommend the user wait until the upgrade completes before taking further action. Users can keep working as normal while the upgrade is in progress. A delay of one day would be highly unusual, but we recommend that users wait that long for the upgrade
complete or to confirm there is an issue.At that time, users should reach out to Microsoft Support or visit a Microsoft Store location so we can look into issues with the PC.
When making significant changes to your computer such as updating the operating system, you should always backup.
See links to resources about backing up by clicking the link for the respective version of Windows you are running:
Windows XP, Windows Vista, Windows 7, Windows 8/8.1
Disable General USB Devices (example - Smart Card Reader).
If you are using a SCSI hard disk, make sure you have drivers available for your storage device on a thumdrive and it is connected. During Windows 10 setup, click the Custom Advanced Option and use the Load Driver command to load the appropriate driver
for the SCSI drive. If this does not work and setup still fails, consider switching to a IDE based hard disk.