If you are talking about the Windows task scheduler, it's already included in your OS, no need to install.
From the Microsoft Help:
Open Task Scheduler by clicking the Start button , clicking Control Panel, clicking System and Security, clickingAdministrative Tools, and then double-clicking Task Scheduler. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
Click the Action menu, and then click Create Basic Task.
Type a name for the task and an optional description, and then click Next.
Do one of the following:
To select a schedule based on the calendar, click Daily, Weekly, Monthly, or One time, click Next; specify the schedule you want to use, and then click Next.
To select a schedule based on common recurring events, click When the computer starts or When I log on, and then click Next.
To select a schedule based on specific events, click When a specific event is logged, click Next; specify the event log and other information using the drop-down lists, and then click Next.
To schedule a program to start automatically, click Start a program, and then click Next.
Click Browse to find the program you want to start, and then click Next.
Click Finish.
If you are talking about the task scheduler withing QV server / publisher, you'll need to license the server / publisher, download the software from QT download site and execute the installer.