Split from this thread.

... we can't sync your calendar because the web calendar service isn't available right now.

If you open the calendar at http://calendar.live.com, is it up to date? If so, on your computer, close down Windows Live mail, then copy the next line, paste it into the start search box and press Enter:

%localappdata%\Microsoft\Windows Live Mail\Calendars

In the folder that opens, right-click the folder that's named with the email address you use to sign in in Windows Live Mail, select Rename and change its name. Now launch Windows Live Mail again and wait a few minutes for the contacts and calendar to load. Then check your calendar again.

I tried the above steps, and it completely removed my WLM calendar.  Where is it, & how can I get it back as it was?