Try using the FileSystemObject. It allows you to perform several tasks on your file system.
Put a timer interrupting from minute to minute and checking if it has reached the pretended hour.
Then you just need to delete the file via FileSystemObject.
Don't forget you must keep the program on for it to execute the task.
Couple of things to consider. Using the System Timer (an API) you can set the timer for much longer intervals than the built-in Timer control. You may also want to consider using the system Task scheduler to fire off the VB program at the appropriate time.
Good Luck
-------------- As a circle of light increases so does the circumference of darkness around it. - Albert Einstein