The Recent projects list reserve the last Five opened projects ,so it is easy to reopen when needed. To remove any project from the list you need to 1- go to the project folder location. 2- Remove the folder to another location or delete it . 3- open the Control builder then go to the recent projects list. 4- click to open the removed project from this list . 5- as you remove the project from the saved pass so it will not open. 6- try again from the recent projects you will not find the project in the list.