http://localhost/security is the direct URI for access.
If you have a disk clean utility or for some reason have deleted any .tmp files then this may be the reason for the blanks.
Look in .\xampp\security\htdocs folder for a file lang.tmp
If it does not exist you can create it in a text editor by adding just the 2 letters of your language, which in your case would be en, then saving the file as lang.tmp in the above directory and re-trying the direct URI.
Or if you have the incomplete Security page up in your browser then simply click on your language in the left frame menu, again in your case it would be English, to reveal the missing items.
Please let the forum know if that fix works for you so as to help future searchers with the same issue.
Also check if all the files are present in the above directory, should be round about 13 files and 2 folders img and lang.
If all else fails you may have to re-install but first make sure all the XAMPP components are stopped and any of the components running as a service are also stopped by uninstalling the particular running service, also very important and often forgotten is stop and uninstall the Control Panel if it too is running as a service.