Endnote’s installer only configures the Microsoft Word CWYW (Cite While You Write) tools for the current user. If you have multiple users on the machine (such as a Limited Access account and an Administrator account), you’ll need to follow the steps in this FAQ to install CWYW on the other account:
http://www.endnote.com/support/faqs/CWYW/faq1.asp#winEN89
The solution is to copy two files (EN9CWYW.dot and EN9Cwyw.WordXP.wll) from your Endnote directory (typically “C:\Program Files\Endnote 9\”) to your Word Startup folder (For Windows XP, its “C:\Documents and Settings\[your UserID]\Application Data\Microsoft\Word\Startup”). The ‘Application Data’ folder is a hidden folder, so you may need to turn on viewing of hidden folders before being able to copy the file. The link above includes instructions for viewing hidden folders.
Administrator accounts can optionally use Word’s “Tools, Templates and Add-Ins, Add” to link directly to the files in the Endnote directory, but Limited Access users must instead copy the files to their Word startup folder, since Endnote requires that those files are opened in read/write mode, and Limited Access users only have read-only access to the Endnote folder.