If lightroom downloaded and installed without any errors, you will get better help with program questions in the program forum
If you start at the Forums Index http://forums.adobe.com/index.jspa
You will be able to select a forum for the specific Adobe product(s) you use
Click the "down arrow" symbol on the right (where it says ALL FORUMS) to open the drop down list and scroll
I am running Windows 8.1 on a PC with an I-7 processor. I had originally downloaded the Lightroom 5 trial. I purchased a subscription to CC in mid December. I uninstalled the trial version when the trial expired and redownloaded Lightroom 5 with my CC subscription. I am not sure if the develop module stopped working or was never working. I have only used the library feature thus far. I am working with the tutorials to learn how to use Lightroom 5.