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TortoiseSVN is a shell-Extension, so wherever you want your SiD-DBD copy to reside, make a right click and choose
- svn checkout
This should bring up the following screen 
Press ok, it will ask you for your CERN account name and password and then check-out the latest version
if you're succesful, you should see the following window 
when you did enter the SiDDBd directory, you'll see the following structure
The green checkmark indicates, that you are in sync with the repository