Welcome BK,
Thanks for reaching out to Microsoft Q&A Forum. I understand that after Windows 11 completed an update, the computer went through account setup again and your previous applications and personal files were no longer available.
Could you please confirm:
- Does the C: drive still show approximately the same amount of used storage as before this happened?
- Was this a normal monthly Windows update, or did Windows install a new Windows 11 version?
Please make sure you already tried the Q&A Assist steps. In addition, please try the following:
1, Check the existing Windows user profiles.
- Press Windows + R > Enter
sysdm.cpland press Enter. - Open the Advanced tab.
- Under User Profiles, select Settings.
- Check whether your previous profile is still listed and note its approximate size.
2, Check Disk Management for other partitions.
- Right-click Start and select Disk Management.
- Check whether the internal drive contains another large partition that does not currently have a drive letter.
- Do not format, delete, or create partitions while the missing files are being investigated.
3, Check whether Windows provides the Go back option.
- Open Settings > System > Recovery.
- Look under Recovery options for Go back.
- If it is available, do not start it yet. Please confirm here first whether the missing files have been located or backed up.
4, Check whether the recent update can be uninstalled.
- Open Settings > Windows Update > Update history > Uninstall updates.
- Check whether the most recently installed update appears there.
- If it does, note its KB number before making any changes.
Looking forward to your update.