Hi, I just thought I would post here after unsuccessfully trawling forums for a solution.
After an install of Xampp I configured my hosts file and httpd-vhosts.conf file. This caused my 404 error.
To fix this I simply commented out my vhosts file and removed my hosts entry. This did not fix the problem, but after a simple reboot my Xampp page was once again accessible at localhost/xampp.
Hope this helps someone out!