I'd like to update my current version of LS to 2.00, and want to back up my current installation directory "at the command-line level", as suggested in the most recent instructions:

"At the command-line level, make a .zip or similar archive of the whole installation directory tree of files. For example in Linux tar cvzf foo.tgz cps100 will tar and zip the whole of the cps100 directory."

I'm using a Windows machine.

cheers

What is your question? How to use a packer under windows?

Download e.g. 7zip
www.7-zip.org/

You can use the GUI or the commandline.
www.7-zip.org/faq.html#user_faq

Thanks...but the current installation directory is in a server...so my question is how to zip a directory that is in a server.

Well, if you don't have access to the windows server to install 7zip you have to ask your server administator what ways he might offer you.

The command line level in Windows is realized in different ways. Most common is RemoteDesktop but there a more ways e.g "Powershell via the Windows Remote Management Service". Sometimes SSH server are installed. Since you asked about comand line level I expected that you have access to the command line.

The is no real difference between your Windows installation and the server you're hosting Limesurvey on when it comes to zipping files. It all depends on the access rights your administrator granted to you.