[BUG] update to 2.1.25 don't work on windows

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/21805
2. https://github.com/anthropics/claude-code/issues/16041
3. https://github.com/anthropics/claude-code/issues/16816

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🤖 Generated with Claude Code

Workaround

The binary can be downloaded directly from Google Cloud Storage and manually replaced:

Direct download URL for 2.1.25 (Windows x64):

https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/2.1.25/win32-x64/claude.exe

Steps:

1. Download the new binary:

``bash
curl -o claude_new.exe "https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/2.1.25/win32-x64/claude.exe"
``

1. Close all running Claude Code instances

1. Replace the old binary (default location: ~/.local/bin/claude.exe):

``bash
mv ~/.local/bin/claude.exe ~/.local/bin/claude_old.exe
mv claude_new.exe ~/.local/bin/claude.exe
``

1. Verify:

``bash
claude --version
# Should output: 2.1.25 (Claude Code)
``

Note: Replace 2.1.25 in the URL with any desired version number for other releases.

I did the workaround, but probably it's not only me who facing this issue.

[like] Ionut Babencu reacted to your message:
________________________________
From: Palkers76 @.*>
Sent: Friday, January 30, 2026 8:33:26 AM
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Subject: Re: [anthropics/claude-code] [BUG] update to 2.1.25 don't work on windows (Issue #21815)

[https://avatars.githubusercontent.com/u/59801882?s=20&v=4]Palkers76 left a comment (anthropics/claude-code#21815)<https://github.com/anthropics/claude-code/issues/21815#issuecomment-3822513453>

I did the workaround, but probably it's not only me who facing this issue.

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same issue here

claude update
Current version: 2.1.23
Checking for updates to latest version...
Successfully updated from 2.1.23 to version 2.1.25

claude

╭─── Claude Code v2.1.23 ──────────────────────────────────────────────────────────────────────────────────────────────╮

had the same issue. manually downloaded and copied into the proper path and it updated. not sure if this was an isolated .23 bug. but confirming authenticity of bug.

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Subject: Re: [anthropics/claude-code] [BUG] update to 2.1.25 don't work on windows (Issue #21815)

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had the same issue. manually downloaded and copied into the proper path and it updated. not sure if this was an isolated .23 bug. but confirming authenticity of bug.

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Me acaba de pasar lo mismo para tratar de actualizar Claude Code de 2.1.31 a 2.1.34

Solución
Ejecuta esto en PowerShell antes de actualizar:

1. Renombra el binario actual

Rename-Item "$env:USERPROFILE\.local\bin\claude.exe" claude_old.exe

2. Ahora sí, actualiza

irm https://claude.ai/install.ps1 | iex

3. Verifica

claude --version

Root cause identified: The Windows binary replacement function (internally N3E in the bundled source) short-circuits when the existing and new binaries have the same file size:

// Simplified from minified source
let existingStat = await fs.stat(executablePath);    // ~/.local/bin/claude.exe
let newStat = await fs.stat(versionedPath);          // versions/<version>
if (existingStat.size === newStat.size)
  return false; // skips replacement entirely

This means any version bump where the win32-x64 binary size is unchanged will silently skip the update — even though the content (and checksums) differ. The GCS manifest confirms identical sizes across affected version pairs, e.g.:

• 2.1.51: size: 235398304, checksum 95d1412c...
• 2.1.52: size: 235398304, checksum 533f6345...

This size check is the only guard before the atomic rename+copy path on Windows. On non-Windows platforms, the function takes a different branch (symlink-based), which is why this is Windows-specific.

Suggested fix: Replace the size comparison with a checksum comparison against the staged binary's known hash (already available from the manifest verification step), or remove the short-circuit entirely — the atomic rename+copy that follows is already safe and idempotent.

This also explains why the rename workaround reported earlier in this thread works: removing the existing file means the stat on the destination throws, the size check is skipped, and the fresh-copy branch executes instead.

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.