Welcome to the forum, Timber Tailor.
The user data is stored according to your o.s. (www.rainlendar.net/cms/index.php?option=com_easyfaq&Itemid=26#faq1
In your case, you need to copy all the files from C:\Documents and Settings\[yourname]\.rainlendar2 to the W7 folder C:\Users\[yourname]\.rainlendar2\
Are you using a portable or full installation? For portable, you can find the ini file in the same folder as the app (usually C:\Program Files\Rainlendar2\)
Are you using only the default calendar or shared network calendar too?