Task Scheduler - Repeat a task on a custom interval that is not selectable

In Windows Server 2008 and above you can set task to repeat on whatever you want. The corresponding drop down menu just present 5,10,15,30 minutes and 1 hour, but you can type in any number of hours or minutes you want to use.

There are some limitations you should know.

You can enter 2 hours, but not 2.5 hours. If you want to run a task every 2.5 hours, you have to enter the amount of minutes. Therefore, this would be 2.5 x 60 = 150 minutes.