JkWorkersFile: Can’t find the workers file specified

I am trying to set up a simple horizonatal Tomcat clustering in windows XP.
Have created a workers.properties file in conf/ directory next to httpd.conf file. However, when trying to start apache using httpd.exe, I am getting the below error.

JkWorkersFile: Can't find the workers file specified

httpd.conf has below entry:

LoadModule jk_module modules/mod_jk.so
JkLogFile "logs/mod_jk.log"
JkLogLevel error
JkMount /TestProject loadbalancer
JkMount /TestProject/* loadbalancer
JkWorkersFile conf/workers.properties

I tried specifying the absoluate path as well
i.e.
JkWorkersFile "C:/Program Files/Apache Software Foundation/Apache2.2/conf/workers.properties"
But still ended up with the same problem.

Below are the entries from workers.properties
workers.tomcat_home=$TOMCAT_HOME
workers.java_home=$JAVA_HOME
ps=/
worker.list=tomcatA,tomcatB,tomcatC,loadbalancer

worker.tomcatA.port=8109
worker.tomcatA.host=localhost
worker.tomcatA.type=ajp13
worker.tomcatA.lbfactor=1

worker.tomcatB.port=8209
worker.tomcatB.host=localhost
worker.tomcatB.type=ajp13
worker.tomcatB.lbfactor=1

worker.tomcatC.port=8309
worker.tomcatC.host=localhost
worker.tomcatC.type=ajp13
worker.tomcatC.lbfactor=1

worker.loadbalancer.type=lb
worker.loadbalancer.balanced_workers=tomcatA,tomcatB,tomcatC
worker.loadbalancer.sticky_session=1

Can anyone help me to resolve this please ?