XPViewer is a standalone application identical to XPSWMM/XPStorm with the exception that the Solve and File Save features are disabled. XPViewer can only open files that have been encrypted and are accompanied by a file with the same name as the XPSWMM/XPStorm model and a .vcf extension.
You must use the same or later version of XPViewer as the XPSWMM/XPStorm the files were created. For example, if the files were created using XPSWMM version 2018.2, you need to open the files using XPViewer version 2018.2. You may encounter some errors when you use an older version of XPViewer than the version in which the model was created.
The installation file may be downloaded from www.innovyze.com. XPViewer and XPSWMM/XPStorm can be installed on the same machine. However, the programs require different .xcf files. It is recommended that the program be installed in a folder such as C:\XPS\XPVIEWER.
The following how to articles give you detailed information about XPViewer: