Download Claude Desktop
First things first: install the Claude Desktop app on your machine. Cowork doesn't run in the browser — you need the app.
Download the appSwitch to Cowork mode
Once you open the app, you'll see three options at the top: Chat, Cowork, and Code. Click Cowork.
Give it access to a folder
Click "Work in a folder" and pick the folder you want Claude to work in. Start with a safe one like Downloads or a specific project folder. Claude can read, edit, and create new files only inside that folder.
Tip: Start with a scratch folder full of files you don't care about, so you can learn how it behaves before handing it anything sensitive.
The best way to start: Download Claude Desktop, switch on Cowork, and pick your Downloads folder. Type "organize this folder for me" and watch the magic happen. The first time you try it, you'll say "why didn't I know about this sooner?"