Enable Windows Calendar To Open In Windows Mail On Windows 7 & 8.

Windows Mail and Windows Calendar are part of Windows Vista but they also run on Windows 7 and 8. But Windows Calendar does not open in Windows Mail as it does in Vista, it needs some help.







I was able to copy the registry keys from my Windows

Vista laptop onto both my Windows 7 and 8 laptops. I ran the reg file and it worked.

I can now open Windows Calendar in Windows Mail and Windows Calendar is also now listed in the Default Programs menu.

Windows Calendar in Windows Mail On Windows 7 but this also works on Windows 8.

To install Windows Mail On Windows 7 and 8 please see this post:

Windows Mail On Windows 8.



To install Windows Calendar on Windows 7 or 8.

On Windows Vista copy the program file which can be found in Programs folder on C Drive.

See also my video.

On Windows 7 and 8.

Place the Windows Calendar Program files that you copied from Vista into the C/Programs folder.


Copy the following registry script.

This is the registry key from Windows Vista.


Here is the registry script.

Copy and paste in notepad or Wordpad.

Save as a reg file.

Then run it  and restart your computer.

You will now be able to open Windows Calendar in Windows Mail on Windows 7, Windows 8 and 8.1. The same as you can on Windows Vista.



 Registry Script:



Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\RegisteredApplications]

"Windows Calendar"="Software\\Clients\\Calendar\\Windows Calendar\\Capabilities"

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar]
@="Windows Calendar"

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar]
@="Windows Calendar"
"LocalizedString"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,\
  6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,\
  00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,\
  77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,2d,\
  00,32,00,30,00,30,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Capabilities]
"ApplicationDescription"=hex(2):40,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,\
  32,00,30,00,34,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Capabilities\FileAssociations]
".ics"="WindowsCalendar.FileIcs.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Capabilities\URLAssociations]
"webcal"="WindowsCalendar.UrlWebcal.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\.ics]
@="WindowsCalendar.FileIcs.1"
"Content Type"="text/calendar"

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\webcal]
@="URL:Webcal Protocol"
"URL Protocol"=""
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,32,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\webcal\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\webcal\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\webcal\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\webcal\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,77,00,65,00,62,00,\
  63,00,61,00,6c,00,20,00,22,00,25,00,31,00,22,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\WindowsCalendar.FileIcs.1]
@="iCalendar File"
"EditFlags"=hex:00,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\WindowsCalendar.FileIcs.1\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\WindowsCalendar.FileIcs.1\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\WindowsCalendar.FileIcs.1\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\Protocols\WindowsCalendar.FileIcs.1\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,69,00,63,00,73,00,\
  66,00,69,00,6c,00,65,00,20,00,22,00,25,00,31,00,22,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Calendar\Windows Calendar\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\WindowsCalendar.FileIcs.1]
@="iCalendar File"
"EditFlags"=hex:00,00,00,00
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,33,00,00,00

[HKEY_CLASSES_ROOT\WindowsCalendar.FileIcs.1\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_CLASSES_ROOT\WindowsCalendar.FileIcs.1\shell]

[HKEY_CLASSES_ROOT\WindowsCalendar.FileIcs.1\shell\open]

[HKEY_CLASSES_ROOT\WindowsCalendar.FileIcs.1\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,69,00,63,00,73,00,\
  66,00,69,00,6c,00,65,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\WinCal.exe]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.FileIcs.1]
@="iCalendar File"
"EditFlags"=hex:00,00,00,00
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,33,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.FileIcs.1\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.FileIcs.1\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.FileIcs.1\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.FileIcs.1\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,69,00,63,00,73,00,\
  66,00,69,00,6c,00,65,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.UrlWebcal.1]
@="URL:Webcal Protocol"
"URL Protocol"=""
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,32,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.UrlWebcal.1\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.UrlWebcal.1\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.UrlWebcal.1\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WindowsCalendar.UrlWebcal.1\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,77,00,65,00,62,00,\
  63,00,61,00,6c,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\webcal]
@="URL:Webcal Protocol"
"URL Protocol"=""
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,32,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\webcal\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\webcal\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\webcal\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\webcal\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,77,00,65,00,62,00,\
  63,00,61,00,6c,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Applications\WinCal.exe]
"FriendlyAppName"=hex(2):40,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,\
  46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,\
  00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,\
  69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,2c,00,32,00,30,00,30,\
  00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Applications\WinCal.exe\shell]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Applications\WinCal.exe\shell\open]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Applications\WinCal.exe\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,22,00,25,00,31,00,22,00,\
  00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Applications\WinCal.exe\SupportedTypes]
".ics"=""

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\WindowsCalendar.UrlWebcal.1]
@="URL:Webcal Protocol"
"URL Protocol"=""
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,32,00,00,00

[HKEY_CLASSES_ROOT\WindowsCalendar.UrlWebcal.1\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_CLASSES_ROOT\WindowsCalendar.UrlWebcal.1\shell]

[HKEY_CLASSES_ROOT\WindowsCalendar.UrlWebcal.1\shell\open]

[HKEY_CLASSES_ROOT\WindowsCalendar.UrlWebcal.1\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,77,00,65,00,62,00,\
  63,00,61,00,6c,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\webcal]
@="URL:Webcal Protocol"
"URL Protocol"=""
"FriendlyTypeName"=hex(2):40,00,22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,\
  00,6d,00,46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,\
  6f,00,77,00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,\
  00,77,00,69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,2c,00,\
  2d,00,32,00,30,00,32,00,00,00

[HKEY_CLASSES_ROOT\webcal\DefaultIcon]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
  00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,43,00,\
  61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,00,61,\
  00,6c,00,2e,00,65,00,78,00,65,00,2c,00,2d,00,32,00,30,00,31,00,00,00

[HKEY_CLASSES_ROOT\webcal\shell]

[HKEY_CLASSES_ROOT\webcal\shell\open]

[HKEY_CLASSES_ROOT\webcal\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,2f,00,77,00,65,00,62,00,\
  63,00,61,00,6c,00,20,00,22,00,25,00,31,00,22,00,00,00

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Applications\WinCal.exe]
"FriendlyAppName"=hex(2):40,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,\
  46,00,69,00,6c,00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,\
  00,73,00,20,00,43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,\
  69,00,6e,00,63,00,61,00,6c,00,2e,00,65,00,78,00,65,00,2c,00,32,00,30,00,30,\
  00,00,00

[HKEY_CLASSES_ROOT\Applications\WinCal.exe\shell]

[HKEY_CLASSES_ROOT\Applications\WinCal.exe\shell\open]

[HKEY_CLASSES_ROOT\Applications\WinCal.exe\shell\open\command]
@=hex(2):22,00,25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
  00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
  43,00,61,00,6c,00,65,00,6e,00,64,00,61,00,72,00,5c,00,77,00,69,00,6e,00,63,\
  00,61,00,6c,00,2e,00,65,00,78,00,65,00,22,00,20,00,22,00,25,00,31,00,22,00,\
  00,00

[HKEY_CLASSES_ROOT\Applications\WinCal.exe\SupportedTypes]
".ics"=""





This integrates Windows Calendar into Windows Mail on 7 and 8 and also lists it in the Default Programs menu the same as it is on  Windows Vista.

Windows Calendar in Default Programs list on Windows 7.This also works on Windows 8.