Testcomplete is not able to open the internet explorer

I am new user i have installed the testcomplete 10.40 version and i have some old test which iam  trying to run but when i run tests , the process  waits for internet explorer to launch to start executing the test and the tool  goes into  infinite time of wating for the browser to launch.Can any body suggest me why it is happending is there any configuration  that i need to do any suggestion would be very helpful for me.