I am working in an environment with several servers running MSCrm 2013. Three of these servers had there D and E drives wiped in error. Unfortunately, CRM was installed on the D: dive. When I tried to re-install CRM I kept getting an error about the UrlRewriteModule. I tried repairing it and I even reinstalled it, but that did not help. Finely, I uninstalled it and then installed CRM. That time it worked. It seems that CRM wants to install the UrlRewriteModule itself. So, if you are having similar problems with any of the Prerequisites, I would recommend going to the control panel and uninstalling them and letting CRM re-install them. I have found that if I get a 500.19 error when I first try to connect to the CRM web page that repairing the UrlRewriteModule fixes that problem.