Hi, I have a disk with Lightroom 1.0 that I have installed a couple of years ago and have been using for a while. I had it backed up several times. I recently had to reinstall my WIndows XP and with it reinstall everything else. When I installed the Lightroom CD it prompted me to download the 1.4.1 update, which I did. And then I tried to open the backed up file - it turned out the backed up Lightroom is 2.7!!! and it cannot be opened with my older version. I am at a total loss. I tried to install Lightroom 2.7 but the serial number I have doesn't work for it. I can't remember at all how my Lightroom got upgraded to 2.7 from 1.0 since I have always had only one disk and one serial number. What can I do now (for free) in order to make the two versions work together and to open my backed up files and to continue using 2.7 (because I am used to having the paintbrush tool and the crop tool under the develop function, and they are not available in Lightroom 1.0). I am sorry for the lengthy description but I am totally ignorant about updates, new versions, etc.