I created one desktop application in C# with installation version.
I installed this application onto the machine. Now I want to open this application by pressing the Ctrl key of keyboard.
That is when the user press the Ctrl key my installed application is open.
How can I open a particular search page of my application by pressing a particular key of the keyboard?
Like the Picasa software.
Well this is no programming but a Windows feature. You have to define a shortcut for that application by opening the property page of that shortcut. There under the shortcut tab you can define the shortcut keys.
For the search key you probably have to attach your main form to the KeyPress event.
Defining key in Shortcut (link) properties would work but not if want just the Control key to activate. To do this you need another application, running in background and auto-starting that listens to keyboard events (hooks).