With only Apache installed you won't get far. You will also need to install MySQL.
Perhaps you can take a look at Xampp (http://www.apachefriends.org/en/xampp.html(http://www.apachefriends.org/en/xampp.html)). This is very easy to install and comes with apache and mysql.
If installed, go to http://localhost(http://localhost) and use phpMyAdmin to create a new database for osticket (write down the database name, user and password).
When the empty database is created you need to create a directory in C:\xampp\htdocs\ (depends on your installation path of course). For example:
C:\xampp\htdocs\support\
In this directory you can copy all the files from the upload folder included in the osTicket download.
Now go to http://localhost/support(http://localhost/support) and follow the osTicket installation steps.
Since I wrote this out of my head, I'm not sure if I covered everything. But basicly you first need to install a webserver and MySQL (Xampp does both) and then you can install osTicket.
Good luck.