If you deleted a sticky note from you Windows 7 by accidnt or simply want to extract it from a dead windows or Windows.old folder simply go to:
RUN and past the following:
Check "Select a program from of a list of installed programs"
Select notepad and open.
You will be able now to find it and read the content.
if you are recovering it from another computer/hardisk or windows.old folder simply just place the drive letter or folder of windows.old.
another more simple method is to show hidden files from tools then browse manually to:
Replace user name with your name, and if recovering from another hardisk "External old disk" change the C: to the drive letter of that harddisk
in case of recovery after upgrade or re-installing windows 7 over another or the same windows.
You can even use hirenboot or Ubuntu Live CD to access your broken system and restore your files plus the sticky notes.
Hope I helped, regards