Get the program Autohotkey from AutoHotkey: macro and automation Windows scripting language
Install program and run.
right click from system tray and press edit script
replace whats in the file with this:
Code:
#Persistent
SetTimer, PressTheKey, 900000
Return
PressTheKey:
Send, {Space}
Return
you can change the 900000 number to the desired length of time (measured in milliseconds so 900000 = 15 mins or 300000 = 5 mins)
save and close the file.
right click tray icon and press reload script and your done.
To turn off simply close program from taskbar.