Sepia tone issue

My black and white photos are shown in sepia tone in the navigator module but showing true black and white on the main screen. Plus when i open the black and white photo from a file on my computer, the photo originally looks pure black and white in the preview but then turns sepia when I open it up. Histogram in the development module also in sepia colour. I have also lost my crop tool, gradiant tool etc in development module. Tried reinstalling Lightroom. Headache!!