How to open a .skill file on Windows

Open it in File Explorer: rename and extract

1. Show extensions. In File Explorer, select View > Show > File name extensions (on Windows 10: the View tab, then tick File name extensions). Without it you can't see the ".skill" part of the name to change it.
2. Rename it. Change vendor-check.skill to vendor-check.zip. If Windows asks whether you're sure, choose Yes. Microsoft says this changes the name only; the file was a ZIP all along.
3. Extract it. Right-click the file, choose Extract All, and follow the steps. Or open it and drag the folder out.
4. Read it. Open vendor-check\SKILL.md in Notepad. The lines between the two --- are the skill's name and description; the rest is its instructions.

Install it in Claude Desktop or claude.ai

1. Check code execution. Anthropic's help says skills need it on.
2. Open Customize > Skills, click +, choose + Create skill, then Upload a skill.
3. Pick the file. Claude's help asks for a ZIP of the skill folder and doesn't mention .skill. If the picker won't take the .skill file, pick the .zip you renamed, not the extracted folder.

If the upload fails, Anthropic lists four reasons: the file is too large, the folder's name doesn't match the skill's name, SKILL.md is missing, or the name or description has characters that aren't allowed. The viewer's checks catch the last three before you try. More detail: how to install Claude skills.

Or put it in Claude Code's skills folder

Claude Code reads skills from folders, not ZIPs. On Windows, ~/.claude is %USERPROFILE%\.claude, so extract the file into %USERPROFILE%\.claude\skills\ and check that you end up with %USERPROFILE%\.claude\skills\vendor-check\SKILL.md, not a folder inside a folder. Claude Code picks it up in the running session; if %USERPROFILE%\.claude\skills didn't exist before, type /reload-skills first, or start a new session. Type /skills to see it. See how to install skills in Claude Code.

Before you install one someone sent you

Anthropic's docs say to use skills only from sources you trust and to audit every file in one you didn't write, looking for network calls, file access or operations that don't match what the skill says it does. A skill can hold scripts that Claude runs. The viewer opens each text file, and so does Notepad once it's extracted.

A worked example: a supplier check on a Windows laptop

Illustration: a made-up business. Daniel buys stock for a three-shop bakery and works on a Windows laptop. The owner sent him vendor-check.skill, made in Claude, and asked him to try it on next week's flour quotes. Before installing it, he dropped it into the viewer:

Files in this skill
vendor-check/SKILL.md

---
name: vendor-check
description: Compares a new supplier's quote with our current prices
  and terms, and lists what to ask before switching. Use when someone
  pastes a supplier quote or price list.
---

Nothing to fix and no scripts. He renamed it to vendor-check.zip, as Claude's help asks for a ZIP, and uploaded it in Claude Desktop under Customize > Skills.

Next step: stop passing the file around

Daniel now has the owner's version from that day. When she adds a rule, he needs a new file. How to send a skill file to a coworker covers what email, Slack and Teams do with the file and the link that replaces it: in AI Skill Pod the skill sits in one pod, and each person reaches it from their own Claude, Cursor or ChatGPT (Pro, Business, Enterprise). Free covers up to 3 members and 10 skills.

Questions

How do I open a .skill file on Windows?

Drop it in the free .skill file viewer to read it in your browser, or rename it to .zip (show file name extensions in File Explorer first), right-click it and choose Extract All. SKILL.md opens in Notepad.

Is renaming a .skill file to .zip safe?

Yes. Microsoft says changing an extension changes only the file's name, not its contents. A .skill file is already a ZIP, so the renamed file is a ZIP Windows can extract, in the shape Claude's upload asks for.

How do I install a .skill file in Claude Desktop on Windows?

In Claude Desktop, open Customize > Skills, click +, choose + Create skill, then Upload a skill, and pick the file. Claude's help asks for a ZIP and doesn't mention .skill; if the picker won't take it, rename it to .zip.

Where do I put a .skill file for Claude Code on Windows?

Unzip it into %USERPROFILE%\.claude\skills, so the skill sits at %USERPROFILE%\.claude\skills\<skill-name>\SKILL.md. Claude Code picks it up without a restart (run /reload-skills first if the skills folder is new); /skills lists it.