Apache gives me 403 Access Forbidden when DocumentRoot points to two different drives

You did not need

Options Indexes FollowSymLinks MultiViews Includes ExecCGI
AllowOverride All
Order Allow,Deny
Allow from all
Require all granted

the only thing what you need is...

Require all granted

...inside the directory section.

See Apache 2.4 upgrading side:

http://httpd.apache.org/docs/2.4/upgrading.html

Somewhere, you need to tell Apache that people are allowed to see contents of this directory.

<Directory "F:/bar/public">
    Order Allow,Deny
    Allow from All
    # Any other directory-specific stuff
</Directory>

More info

For Apache 2.4.2: I was getting 403: Forbidden continuously when I was trying to access WAMP on my Windows 7 desktop from my iPhone on WiFi. On one blog, I found the solution - add Require all granted after Allow all in the <Directory> section. So this is how my <Directory> section looks like inside <VirtualHost>

<Directory "C:/wamp/www">
    Options Indexes FollowSymLinks MultiViews Includes ExecCGI
    AllowOverride All
    Order Allow,Deny
    Allow from all
    Require all granted
</Directory>