This article applicable to standalone license only. Hosted version’s database is in the cloud.
Where are database files located?
Windows XP:
c:\Documents and Settings\(user name)\inTennis\database
Windows 7 or Vista:
c:\Users\(user name)\inTennis\database
Mac OS X:
Places > (user name) > Library > Application Support > inTennis > database
or
~/Library/Application Support/inTennis/database