C:\Weatherlink certainly isn't the _only_ location that can be used
and whatever works for you is fine of course. However:

Any location within \Program Files\ really is best avoided. For some
time Windows has prevented programs writing back configuration data to
locations within \Program Files\ hence the various error messages and
odd behaviour that can result. Windows 7 etc does have automatic
internal workarounds to mitigate this but the installation can still
end up less than robust and with the data files being tricky to find.

C:\Weatherlink is the default location that's been used for some time
now and is where WL automatically looks when new updates are
installed. For locations other than C:\Weatherlink, updates need to be
done more carefully to ensure that the overall installation doesn't
get split and hence stop working.

I've never really looked at this in detail, but for USB loggers I
suspect that the USB driver doesn't install into the main WL folder
but elsewhere. If this is true then simply copying the WL folder to a
new PC (ie an xcopy approach) probably won't give a functional
installation because there won't be communication with the logger.

There's a distinction between where the main WL folder is located and
where the data files are placed. By default, these are both in the
C:\Weatherlink folder but they don't have to be. As above, I'd still
suggest that C:\Weatherlink is best for the main executables etc.
However, when you create a new station, this (and hence all the
resulting data files) can be located anywhere that you have reliable
write access. So the station folder could certainly be located in a
Dropbox folder to give you automatic data backup (or any one of the
other folders used by similar backup/synchronisation services, most
obviously Onedrive (as used to be Skydrive)).

JGD

The problem with installing into C:\Weatherlink is that if you have
Windows 8.1 File History won't backup the data and I don't think it is
possible to configure file history to include this directory - if anyone
knows otherwise I am sure they will say that I am wrong.

With Windows 7 and Windows 8, Windows 7 backup is available which will
backup all files.

I have installed the product to a dedicated folder in the 'My
Documents' folder which means the files are backed up automatically.

Davis should modify the product so the executables are held in a Program
Files directory and the data is saved in a dedicated 'My Documents'
folder, it's how most software products work such as Microsoft Office.

Alan