This "Task Scheduler" utility is available in Windows "Control Panel" by the name "Scheduled Tasks". Detailed steps are described as under.
1) Say our aim is to automatically run the file by the name QTP_Test.vbs available at the location C:\ExpertQTP\QTP_Test.vbs
2) Go to Windows "Control Panel" -> "Scheduled Tasks".
3) Click on "Add Scheduled Task" in the "Scheduled Tasks"
4) This will start the "Scheduled Tasks Wizard".
5) Click on "Next" - > Browse - > In "Select Program to Schedule" screen Go to the location of the QTP_Test.vbs file available in C:\ExpertQTP folder - > Click "Open" as described in the following picture.
6) In the "Scheduled Tasks Wizard" select the schedule for running the QTP Script. For example Daily, or Weekly or Monthly as per various options offered in the Wizard. In or example select say "Daily". Then Click "Next" as described in the following picture.
7) Select the Time & day you want to start this Script. Then Click "Next" as described in the following picture.
8) Enter the "User Name" & Password for the workstation, just only once as described in the following picture.