How can I reset a local admin password on an old Windows 7 machine?

You might be thinking of Hiren's BootCD. It provides a bootable environment with recovery tools, including options for working with local account passwords. Check that the version you choose supports the machine's hardware and can see the RAID volume before changing anything.

Offline NT Password & Registry Editor, also known as chntpw, is another option for Windows 7 local accounts. It edits the account database offline rather than recovering the existing password. The Windows volume needs to be accessible from the boot environment, so RAID drivers or disk encryption can complicate things.

If you have access to Microsoft Diagnostics and Recovery Toolset, or DaRT, it includes a local password reset tool. Availability and compatibility are worth checking for an old Windows 7 installation, including whether the recovery environment matches the machine's architecture.

There is also a recovery-environment workaround that temporarily replaces the sign-in screen's Ease of Access executable with Command Prompt, then uses net user to reset the local password. It requires access to the Windows installation offline and won't bypass full-disk encryption. If you use that route, restore the original executable afterward.

Since the goal is data recovery, first make sure the recovery environment can see the RAID and that you have any encryption recovery keys needed. A password reset alone won't solve either problem.