I have setup windows server 2008 enterprise as well and initially had the same problem.
To correct the problem do the following:
(1) Edit the xampp/apache/conf/httpd file
(2) Local the keyword "Listen"
(3) After the last entry enter additional listen entries e.g.
in this case my port number is set to 92. Be careful not to use port 80, which is the default in the httpd file. Port 80 is also used by Windows http server.
(5) Save the file and restart XAMPP Control Panel.
(6) Next, get xampp using the following URLs (1) Localhost:92 or (2) http://192.168.1.51:92
(7) This should work fine.
This should now work.