The vanished project folder in a 24-machine school lab

Order matters because every write to the disk reduces the chance of recovery.

1. Stop using the affected machine. Ask the class to move to another PC; do not install, download or clean anything yet. Deleting files to free space first is the classic mistake - it overwrites clusters that may still hold the deleted folder.
2. Check the Recycle Bin under the Student account on that specific machine. A normal delete from Desktop lands there; a Shift+Delete or a delete from a network or removable location does not. Restore to a different folder, not to Desktop, so a second accidental delete cannot repeat the loss.
3. Check Previous Versions. Right-click the Desktop folder, Properties, Previous Versions tab. If System Protection or File History was enabled, a snapshot may exist. The school has no server, so this is the only realistic local recovery route and it must be checked before any cleanup.
4. Search the whole disk and the external disk for *project* with a date filter, and look in %TEMP% and the Office AutoRecover or UnsavedFiles folders, since Word, Excel and PowerPoint often hold a recent copy. Check whether the student emailed or uploaded a draft to the shared Google account - the shared account is bad practice, but here it may be the rescue.
5. Only after recovery attempts, free space on 7, 12 and 19: Storage Sense and Disk Cleanup, clear Downloads and Videos after confirming nothing required is there, move the surviving student work to a data partition or the external disk, uninstall unused packages, and set a minimum free-space rule (for example 15% of C:) so the situation is visible before it becomes critical.

Record what was done and when. If step 3 yielded nothing, the honest conclusion is that the file is unrecoverable and the student must be given time to rebuild - do not spend the day on undelete tools while three machines remain unusable.

Without a domain, keep it deliberately simple: a small fixed number of accounts, one shared working area, and permissions that assume students will click things.

Accounts (per machine). Remove the single shared 'Student' account. Create one standard account per batch - Lab09, Lab10, Lab11 - plus one administrative account, LabAdmin, whose password is known only to the assistant and the head of department. Students log in as their batch account. This is not individual accountability, but it stops Class 9 seeing Class 11's work and stops any student installing software.

Folders. Create a data partition D:/Work/Class09, Class10, Class11, each with one subfolder per roll number, and an Inbox folder for submissions. Desktop is left empty and used for nothing - this directly addresses the disappearing folder.

Permissions. Grant the batch account Modify on its own class folder only; grant Read on other class folders; deny Write to D:/Work root, so students cannot delete the class folder itself, only files inside their own. Set the Inbox to Write-only (students can drop files, cannot read or delete others).

Naming convention. <roll>_<subject>_v<n>_<YYYY-MM-DD>, for example 11-024_IT_project_v02_2025-01-14. Version plus date removes the 'final 2 copy' ambiguity and makes the latest file obvious.

Marks file. It must leave the shared Desktop today. Move marks_all.xlsx into the LabAdmin profile (or onto the external disk) and protect it with a password on open, plus sheet protection. A marks file in a shared folder is a data-protection issue as much as an academic one.

Housekeeping. Enable Storage Sense on every machine with a 30-day Downloads rule, and set a monthly 20-minute routine: clear temp files, check free space on all 24, and copy D:/Work to the external disk.

Propose a two-copy, alternating schedule that the assistant can actually keep:

• Weekly local copy. Every Friday after the last period, copy D:/Work from each machine to the external disk into a folder named by date, for example 2025-01-17/PC07/. Keep the last four weeks and delete the fifth - 24 machines of student work is small, but C: drives are not, so copy only the work partition.
• Monthly off-site copy. Once a month the assistant takes the external disk home or to the principal's residence for the weekend, then returns it. This is the only part that protects against fire, theft or a power surge in the lab.
• Cloud for submissions only. Use the 40 Mbps link for the Inbox: a single per-class Google Drive folder owned by a staff account, not the shared account, to which students upload final submissions. This is a convenience copy, not the primary backup, and it must not contain marks or personal data unless the account is properly controlled.
• Restore test. Once a term, restore one folder from the external disk to a spare machine and open a file from it. An untested backup is an assumption, not a control.

The main risk to state plainly: the whole scheme depends on one person remembering a Friday routine, and a single external disk that lives in a cupboard is a single point of failure. If the assistant is absent for three weeks, nothing is backed up and nobody notices. The mitigation is a one-page checklist signed and dated each week and kept in the lab, with the head of department as named alternate. Also flag that the shared Google account is unsuitable for anything containing student personal data - it defeats the point of the new permissions.