http://windows.microsoft.com/en-IN/windows7/Create-keyboard-shortcuts-to-open-programs
You can create keyboard shortcuts to open programs. Before you get started, you need to create a shortcut for the program to which you want to assign a keyboard shortcut. To do this, open the folder that contains the program’s executable file, right-click it, and then click Create Shortcut. For more information about creating shortcuts to programs, see Create or delete a shortcut.
1. Locate the shortcut to the program that you want to create a keyboard shortcut for.
2. Right-click the shortcut, and then click Properties.
3. In the Shortcut Properties dialog box, click the Shortcut tab.
4. Click in the Shortcut key box, press the key on your keyboard that you want to use in combination with Ctrl+Alt (keyboard shortcuts automatically start with Ctrl+Alt), and then click OK. 
If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
If you’re using a program that also has a keyboard shortcut using the same key combination as the shortcut you just created, then your shortcut might not work.
Notes
· The word None appears in the Shortcut key box until you press a key; then it’s replaced with Ctrl+Alt+the key that you pressed.
· You can’t use the Esc, Enter, Tab, Spacebar, PrtScn, Shift, or Backspace keys to create a keyboard shortcut.
