You can currently stream the series for free (usually with ads) on these platforms: Tubi The CW App/Website Plex Where to Buy Digitally
If you prefer to own a permanent digital copy without ads, it is available for purchase on: The Lost Room - streaming tv show online - JustWatch
While there are many places to find online, using third-party torrent sites can expose your device to security risks like malware or legal issues. Instead, you can find the entire 2006 miniseries across several high-quality, legitimate platforms—often for free. Where to Stream "The Lost Room"