If everything works, you can either keep using Ubuntu-D, or later remove the old C: distro with:
wsl --unregister Ubuntu
⚠️ Only run --unregister after you have tested the new distro and kept the .tar backup somewhere safe. That command deletes the old distro.
OpenClaw’s important data is normally under ~/.openclaw, including config, credentials, sessions, auth profiles, and workspace. Docs: https://docs.openclaw.ai/help/faq-first-run and backup command: https://docs.openclaw.ai/cli/backup
About buying a SATA SSD: good idea for backups / portability, not my first choice for running live WSL if it’s external/removable. For daily use, D: on an internal SSD/NVMe is better. A SATA SSD is totally fine as a place to store openclaw backup archives or WSL export .tar files, and you can import that onto another PC later.
For moving to another PC later, safest flow is: install WSL/OpenClaw there → copy the backup/export over → import/restore → run openclaw doctor.