ocr: Specitier Description <INSTALLDIR> The main installation directory specified by the user. <WINDIR> The Windows directory, <WINSTSDIR> The Windowsisystem directory. <WINDISK> The drive that the Windows directory resides on, for example, C:. <WINSTSDISK> The drive that the Windows system directory resides on. <WINSYS16DIR> On . an NT system this is the 16- bit Windows directory. <PROGRAMFILESDIR> The Program Files directory. <COMMONFILESDIRS The Program Files/Common Files directory, Figure 7: Instalishield Express directory specifiers.