"Red Alert 2 installation is damaged" error

[~Guest~]

2011-01-04 20:08:16 Initialization started.
2011-01-04 20:08:16 Loading options...
2011-01-04 20:08:16 Red Alert 2 install path established: C:\Westwood\Red Alert 2
2011-01-04 20:08:16 Red Alert 2 installation is not from The First Decade DVD.
2011-01-04 20:08:16 Checking for free disk space.
2011-01-04 20:08:16 Confirming safe files...
2011-01-04 20:08:16 Loading plugins...
2011-01-04 20:08:16 Loading mods...
2011-01-04 20:08:16 Your Red Alert 2 installation is damaged. Unrecognized Red Alert 2 version. Please reinstall Red Alert 2.
2011-01-04 20:08:19 Program terminating.
2011-01-04 20:08:19 'Persistent Plugins' is disabled. Deactivating all plugins...
2011-01-04 20:08:19 Saving settings.


I downloaded Red Alert 2 from http://xwis.net/downloads/

Is there anything I forgot to mention?