I work with the link below for my window 8 laptop. I worked fine.

Step-by-Step

STEP 1. Install WAMP server and Oracle 11g at first.
STEP 2. For Windows 7 (64-bit), extract instantclient-basic-windows.x64-11.2.0.3.0.zip, downloaded from http://www.oracle.com/technetwork/topics/winx64soft-089540.html to C:\Windows\SysWOW64\instantclient_11_2 and set it on PATH variable for Environment variable.

STEP 3. Reboot the system now.
STEP 4. Allow PHP extension from php.ini as
extension=php_oci8_11g.dll (just remove the ";" from the start of the line)
STEP 5. Restart WAMP server.
STEP 6. Open the file to see the database name as D:\app\Farhan\product\11.2.0\dbhome_1\NETWORK\ADMIN\tnsnames.ora
 LISTENER_ORCL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))


ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )

ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )
Here, the service name is found as "orcl" .
STEP 7. Make the connection in PHP script as oci_connect(your_username, your_password, "localhost/orcl.168.1.2");

Conclusion

Now try it on your environment, wish you will be succeeded easily to connect with Oracle database from PHP applications on the platform of Windows 8.

Source: http://www.codeproject.com/Tips/523381/PHP-with-Oracle-11g-on-Windows-7-64-bit