Desktop shortcuts on Windows 7 will suddenly disappear from your desktop if they are unused for a while or if they connect to a network resource that is unavailable. This is particularly annoying on laptop and netbook PCs where you can't always be connected to network resources. Happily there is an easy but obscure way to stop Windows 7 from automatically removing shortcuts from your desktop.
Go to START > All Programs > Accessories > System Tools > Task Scheduler (or just search for "Task Scheduler").
In the left-hand pane expand "Task Scheduler Library", expand "Microsoft", expand "Windows", and highlight "Diagnosis".
Right-click on "Scheduled" (next to the clock icon) and select "Disable". The status will change to "disabled" and you can exit the Task Scheduler.
This will stop Windows 7 from automatically removing shortcuts form your desktop.