Claude Cowork deleted about 275 GB from a user's C: drive after being told to delete one group of leftover files, the user reports
Told to delete only the first group of leftover application files, Claude Cowork on Windows ran a recursive delete that removed about 275 GB from the user's C: drive, the user reports in a GitHub issue.
A user running Cowork in Claude for Windows 4.29.0, with the model shown as Opus 5.5 and Accept Edits on, had Cowork sort leftover files from uninstalled applications into groups. The user authorized only "Delete the first group" and says they never authorized deleting the C: drive root, personal documents, or application data1.
Cowork reported that 26 folders were deleted and that the remaining 5 needed admin rights. In the next step it said a "$WinREAgent" path had expanded to C:\ itself. It then reported that C: usage had dropped from 413 GB to 138 GB because "the bad recursive delete command wiped out a lot of data before erroring out," halted all writes, and told the user "about 275 GB on C: was deleted by mistake"1.
The issue was filed on October 30, 2026. It had no comments or Anthropic response at the time of review1.
The user ran Cowork in Claude for Windows 4.29.0, with the model displayed as Opus 5.5 at medium effort and Accept Edits on.
“Opus 5.5, Medium effort”
The user authorized only the deletion of the first group of files Cowork had identified.
“Delete the first group”
The user says they did not authorize deletion of the C: drive root, personal documents, application data, or unrelated system files.
“I did not authorize deletion of the C: drive root, personal documents, application data, or unrelated system files.”
Cowork reported deleting 26 folders and said the remaining 5 needed admin rights.
“26 folders are deleted. The remaining 5 need admin rights (a UAC prompt will appear).”
Cowork then said a $WinREAgent path had expanded to C:\ itself.
“I hit a bug where the $WinREAgent path expanded to C:\ itself”
Cowork reported that C: usage dropped from 413 GB to 138 GB because a recursive delete command wiped out data before erroring out, and halted all write operations.
“C: usage dropped from 413 GB to 138 GB — the bad recursive delete command wiped out a lot of data before erroring out. I'm halting all write operations”
Cowork told the user that about 275 GB on C: had been deleted by mistake.
“I caused a serious accident: about 275 GB on C: was deleted by mistake. I'm very sorry.”
Measurements
C: drive usage before and after the delete, as Cowork reported it1
Table
| Item | Value |
|---|---|
| Before | 413 GB |
| After | 138 GB |
All 7 claims with their quotes
- The user ran Cowork in Claude for Windows 4.29.0, with the model displayed as Opus 5.5 at medium effort and Accept Edits on.1
“Opus 5.5, Medium effort”
- The user authorized only the deletion of the first group of files Cowork had identified.1
“Delete the first group”
- The user says they did not authorize deletion of the C: drive root, personal documents, application data, or unrelated system files.1
“I did not authorize deletion of the C: drive root, personal documents, application data, or unrelated system files.”
- Cowork reported deleting 26 folders and said the remaining 5 needed admin rights.1
“26 folders are deleted. The remaining 5 need admin rights (a UAC prompt will appear).”
- Cowork then said a $WinREAgent path had expanded to C:\ itself.1
“I hit a bug where the $WinREAgent path expanded to C:\ itself”
- Cowork reported that C: usage dropped from 413 GB to 138 GB because a recursive delete command wiped out data before erroring out, and halted all write operations.1
“C: usage dropped from 413 GB to 138 GB — the bad recursive delete command wiped out a lot of data before erroring out. I'm halting all write operations”
- Cowork told the user that about 275 GB on C: had been deleted by mistake.1
“I caused a serious accident: about 275 GB on C: was deleted by mistake. I'm very sorry.”
Sources
Related incidents
- AID-2026-0121 Claude Code deleted a user's entire unversioned game project when asked to free disk space, the user reports
- AID-2026-0126 Codex ran a malformed node_modules cleanup command that deleted files across a user's entire SSD partition, the user reports
- AID-2026-0112 Claude Code pointed a destructive self-test at a user's real repository through a symlink, erasing its Git history, the user reports
- AID-2026-0125 A Claude Code subagent wrote a test that ran rm -rf ~ on a user's real home directory despite worktree isolation, the user reports
Editor notes
Based on a single first-hand GitHub issue opened 2026-10-30; the day of the deletion itself is not stated, so `date` is 2026-10. The user's authorization was written in Chinese ("删除第一组"); the English rendering "Delete the first group" is the reporter's own. Cowork's messages are quoted as the reporter gives them; no logs or screenshots are public (the reporter says full logs will go to support privately). The cause (a path variable expanding to C:\) is the agent's own explanation and is unverified. The report is internally inconsistent: Cowork first says 26 folders were deleted, then "The 4 folders were deleted". The reporter's list of possibly affected locations (Documents, Desktop, Downloads, AppData, WSL data) and the claim that files bypassed the Recycle Bin were left out as unverified. Drafted without the Gemini writer (OpenRouter out of credits); quotes checked by the editor against the issue page. No comments or Anthropic response as of 2026-10-30.