I installed Lightroom 5 on my laptop with Windows 8 and was able to import and export photos. On another occasion I imported photos, deleted some, tried to import others and the whole system crashed. Troubleshooting tells me Lightroom 5 is an incompatible program. Why is this when it was perfectly OK to start with. It also tells me the installation source for this program does not exist. I am at a loss as to how to fix it. I have uninstalled and reinstalled it 3 times but it still does not work. What can I do?