Windows Calendar is not included in Windows 7,but can be reinstated on Windows 7 and Windows 8.If the Windows Calendar program files are copied over from Windows Vista onto Windows 7 and Windows 8.
source: Windows Calendar - Wikipedia, the free encyclopedia
also how to get the calendar in windows 7... Download Windows Calendar For Windows 7
you will need to copy the contents of the calendar in vista before making the change, im not sure exactly where its located ,probably in appdata ,its a hidden file,
will have a look
edit: this page here http://www.techrepublic.com/blog/win...s-calendar/718
will tell you how to back up the current content ,then you can install it into the calendar when you install it in Windows 7.
edit: it seems the link above no longer has the calendar download link, im sure more googling will find it or a how to extract it from your vista to install it in 7.