If disappeared shortcuts to network files from desktop

If you create desktop shortcuts to removable storage places such as NAS the icons will disappear from time to time because Windows 7 has a built in task schedule to clean up broken and unused links. 
To prevent the task from running you need to disable the task in the Task Scheduler: start-> programs-> accessories-> system tools-> task scheduler
Expand the tree in the left hand pane until you get to Task Scheduler Library -> Microsoft -> Windows -> Diagnosis.
In the right hand pane, right click the task named Scheduled and click Disable.