apache 2.2 - httpd server is not starting

I am implementing failover mechanism in JBoss from here

I added following line in httpd.conf file

LoadModule jk_module modules/mod_jk.so

Now I am getting following error while starting Apache

D:\Installation\apache-2\bin>httpd -k start
httpd: Syntax error on line 495 of D:/Installation/apache-2/conf/httpd.conf: Can

not load D:/Installation/apache-2/modules/mod_jk.so into server: The specified
procedure could not be found.

I am sure that there is file mod_jk.so in modules directory. What could be reason for this and how to resolve this problem?
I am using Wondows 7 OS.
Thanks in advance