If after restarting the server you get errors, you may need to set your directory options as well. This is done in the <Directory> tag in httpd.conf. Make sure the final config looks like this:
DocumentRoot "C:\alan"
<Directory "C:\alan">
Options Indexes FollowSymLinks
AllowOverride All
Order allow,deny
Allow from all
</Directory>
For me it was on line 183, but it only works after you reboot your computer. I wish there was a way to quickly change it without having to reboot each time, but for now that's the only way I know how.
@Hooman: actually with the latest versions of Xampp you don't need to know where the configuration or log files are; in the Control panel you have log and config buttons for each tool (php, mysql, tomcat...) and clicking them offers to open all the relevant file (you can even change the default editing application with the general Config button at the top right). Well done for whoever designed it!
I had to change both the httpd.conf and httpd-ssl.conf files DocumentRoot properties to get things like relative links (i.e. href="/index.html") and the favicon.ico link to work properly.
The latest Xampp control Panel makes this pretty easy.
From the control panel, there should be Apache in the first row. If it's started, stop it. Then click config and open the httpd.conf file and search for htdocs or documentRoot. Change the path to what you like. Do the same for httpd-ssl.conf. These should be the top 2 files in the list under Config's dropdown.
On Linux Mint (Debian Based) go to /opt/lampp/etc/httpd.conf
Find YOUR_OWN_FILES_LOCATION to, of course, your files location.
DocumentRoot "YOUR_OWN_FILES_LOCATION"
<Directory "YOUR_OWN_FILES_LOCATION">
#
# Possible values for the Options directive are "None", "All",
# or any combination of:
# Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
#
# Note that "MultiViews" must be named *explicitly* --- "Options All"
# doesn't give it to you.
#
# The Options directive is both complicated and important. Please see
# http://httpd.apache.org/docs/trunk/mod/core.html#options
# for more information.
#
#Options Indexes FollowSymLinks
# XAMPP
Options Indexes FollowSymLinks ExecCGI Includes
#
# AllowOverride controls what directives may be placed in .htaccess files.
# It can be "All", "None", or any combination of the keywords:
# Options FileInfo AuthConfig Limit
#
#AllowOverride None
# since XAMPP 1.4:
AllowOverride All
#
# Controls who can get stuff from this server.
#
Require all granted
</Directory>