Unless explicitly stated otherwise, a per user installation is the default installation type of all SST, software setup packages. It installs, patches, or updates software, on a per user account basis. That is, on a NT-based (i.e. Windows NT 4.0, 2000, XP, Vista, Windows 7, and later) system, with the user accounts Jane and John, if the software is installed under Jane's user account, the software will be installed for exclusive use by Jane, and John will not be able to use the software unless he also installs the software under his user account.

In contrast to per machine installations, per user installations can be performed under any user account with adequate privileges to install (and uninstall/remove) software. Although this is applies to the default user privileges of most NT-based operating systems, recent and current versions of Windows with User Account Control (UAC) (e.g. Vista and Windows 7) may require elevated privileges to install the SST product(s). Nonetheless, a per user installation is recommended for most users.

Because per user installations are the default installation type, they do not need to be explicitly selected or specified on the command line, even when performed under an account with administrator privileges.

For step by step guides on how to perform a per user installation please see Installing a Product by Means of a Web Setup Package, Installing a Product by Means of a Self-Extracting Setup Package, and Installing a Product by Means of a Disk Setup Package, under Using the Setup Launcher

Unlike per user installations, a per machine installation (automatically) makes the (installed) software available under all user accounts on a particular computer, including local user accounts that are created after the software has been installed. Unfortunately, the downside of a per machine installation is that it has to be performed under an administrator account. In other words: Elevating the privileges to administrator, either prior to installation or on-demand, under a guest, user, power user, etc. account, does not suffice to perform a per machine installation. Under newer Windows versions, particularly those with User Account Control (UAC), this may involve creating and/or modifying user accounts.

Furthermore, for technical reasons, a per machine installation may also require removing remnants of the (installed) software manually, (both) from the file system and/or the registry, when the software is uninstalled.

A per machine installation can be selected in the Setup Launcher's Query All Users Dialog (which click here to see) of all (i.e. the web, disk, and the self-extracting) setup packages. If a dialog of this nature is not displayed, your system and/or the account under which the installaiton is being performed does not fulfill the criteria for a per machine installation and a per machine installation should not to be attempted.

For step by step guides on how to perform a per machine installation refer to Installing a Product by Means of a Web Setup Package, Installing a Product by Means of a Self-Extracting Setup Package, and Installing a Product by Means of a Disk Setup Package, under Using the Setup Launcher

Administrative installations are essentially only a form of pseudo-installation, in that they do not install the software for direct use by individual users under their own user account(s). Instead, they provide a single installation source for numerous users, commonly, but not necessarily, located on a network server. Users with access to this local or network location can then install the software on their own computers from the source created by the administrative installation.

Because the target folder of the administrative installation is comparatively easy to administer and this installation type permits an end-user installation of the software in which most of the software's files can remain in the central installation repository ("run from source"), this type of installation is recommended primarily for medium to large LANs or WANs. As it requires experience in managing access rights and user accounts, it is less suited for smaller networks without a permanently accessible server and stand-alone computers.

Administrative installations are initiated by specifying "-a" or "/a" (without the quotation marks) on the command line.

For step by step guides on how to perform an a installation please see Installing a Product by Means of a Web Setup Package, Installing a Product by Means of a Self-Extracting Setup Package, and Installing a Product by Means of a Disk Setup Package, under Using the Setup Launcher

While it is perfectly OK to mix a per machine or a per user installation with an administrative installation, it is not recommended to mix per user with per machine installations, as this may lead to unpredictable results when the software is uninstalled.

Of the two Microsoft Windows product ranges, only the operating systems based on Windows NT (i.e Windows NT versions 3 and 4, 2000, XP, Vista, etc.) have fully segregated user accounts. Although Windows 9x operating systems (i.e. Windows 95 up to and including Windows Millenium Edition (ME)) also support multiple user accounts on the same computer, these are only partially segregated.