Microsoft Word
Once you download and install Mendeley Desktop to a computer, you can install the Microsoft Word Plugin. Open the Desktop, then click on Tools > Install MS Word Plugin. You may have to close and reopen Word for the install to be completed.
OpenOffice
If you use OpenOffice on a Linux or Windows machine, you should be able to install the plugin by downloading and installing Mendeley Desktop and then clicking Tools >Install OpenOffice Plugin in the program window. For more help, log onto Mendeley Web, click on Search, then Support, and use keywords to search for your troubleshooting topic.