Upgrading Lightroom 6 [Need link for Lightroom 6.7 update]

I have just bought a new laptop, my old one died, and I have installed Lightroom 6 from my purchased disc. My version is Lightroom 6.0 and I need to upgrade it to the latest version of Lightroom 6, which I have on my desktop and which was on my old laptop, so that I can read the raw files on my cameras. The upgrade facility in Lightroom no longer works - how can I get the latest version?