How to Relocate Ethereum Wallet Data with Windows Hard Links

When the Ethereum Wallet is installed and started, it automatically syncs the blockchain to a default folder on Windows: C:\Users\Administrator\AppData\Roaming\Ethereum, containing geth and keystore subfolders. As synchronization progresses, the geth folder can grow to dozens of gigabytes, quickly exhausting space on computers with small C: drives.

Solution Overview

The wallet itself does not offer a configuration option to change the data directory, so the workaround relies on Windows command‑line utilities to create a hard link (junction) that redirects the default path to a location on another drive.

Creating a Hard Link

Open a Command Prompt (cmd) with administrator rights and run the following command, adjusting the paths to match your system:

mklink /j C:\Users\Administrator\AppData\Roaming\Ethereum D:\EthereumData

/j

creates a directory junction (hard link).

The first path is the original folder that the wallet expects.

The second path is the actual directory where you want to store the blockchain data.

After the link is created, the wallet will read and write to the new location transparently. In Windows Explorer, the linked folder shows a shortcut arrow and a lighter icon.

Removing the Hard Link

To revert, simply delete the junction folder on the C: drive (the link itself), which does not affect the data stored in the target directory.

Common Issues

If you encounter "access denied" errors when launching the command, run the Command Prompt as an administrator (right‑click → "Run as administrator") or use the Win+R dialog to start cmd with elevated privileges.

Final Notes

If you have further questions, you can leave a comment or contact the author via the provided QQ group (659809063). The author also mentions an ongoing Java wrapper for the Geth client API, available on request.