Installer Exit Codes¶

This page describes the exit codes returned by the Windows installer (prism-<version>-setup.exe) for every install scenario, and the values to submit for each scenario in the Microsoft Store package step.

Prism's installer is built with Inno Setup 6. Inno's Setup.exe terminates with a process exit code that describes how the installation ended. The Microsoft Store package submission requires you to map each of its install scenarios to an EXE return code value, and its validation rejects a submission in which two scenarios share the same value. Every scenario below therefore carries a distinct value.

Who consumes these codes

Microsoft Store — the Installer handling step of the package submission consumes the values in the mapping table below.
Deployment scripts — silent installs (/VERYSILENT) are usually driven by an orchestrator that branches on the process exit code.
Users — an interactive install reports problems in the wizard UI instead of relying on the exit code.

Exit codes¶

The complete range of exit codes used by the Prism installer:

Exit code	Meaning	When the installer returns it
`0`	Installation successful	Setup ran to completion, or `/HELP` / `/?` was used.
`1`	Installation already in progress	Setup failed to initialize. Not reachable in the shipping installer: the single-instance guard is the `SetupMutex` directive, and `prism.iss` wires no `SetupMutex`, so a second instance runs freely. Kept as a reserved value for a future single-instance guard.
`2`	Installation cancelled by user	The user clicked Cancel in the wizard before the actual installation started, or chose No on the opening message box.
`3`	Miscellaneous install failure	A fatal error occurred while preparing to move to the next installation phase. Reported as a miscellaneous failure; the conditions are rare (out of memory or Windows resources).
`4`	Miscellaneous install failure	A fatal error occurred during the actual installation process. Errors behind an Abort/Retry/Ignore box are not fatal: choosing Abort there yields `5`.
`5`	Installation cancelled by user	The user clicked Cancel during the actual installation process, or chose Abort at an Abort/Retry/Ignore box.
`6`	Miscellaneous install failure	The `Setup.exe` process was terminated by the debugger. Not reachable in production.
`7`	Disk space is full	The Preparing to Install stage determined that the installation cannot continue because the target volume has insufficient free space.
`8`	Reboot required	The Preparing to Install stage determined that the installation cannot continue and that a system restart is required to correct the problem.
`100`	Application already exists	An earlier installation of Prism is already registered on the device. Reported via the custom exit code mechanism below.
`101`	Network failure	Reserved. The installer fetches no remote payload, so no condition raises this code today; it is kept so the Store scenario has a value of its own.
`102`	Package rejected during installation	Reserved. Set it from a device-side security-policy check when one is added; kept so the Store scenario has a value of its own.

!!! note "Before returning 1, 3, 4, 7 or 8, an error message explaining the problem is normally displayed — see Inno Setup's Setup exit codes. Any exit code other than 0 means the installation was not run to completion. Future versions of Inno Setup may add exit codes, so callers must handle unexpected values as a failure rather than matching only the list above."

Microsoft Store package submission¶

Enter these values in the Installer handling step of Partner Center. The documentation URL required for the miscellaneous return codes is Inno Setup's exit-code reference: https://jrsoftware.org/ishelp/topic_setupexitcodes.htm

Store scenario	EXE return code	Origin of the value
Installation cancelled by user	`2`	Inno Setup
Application already exists	`100`	Prism installer (custom)
Installation already in progress	`1`	Inno Setup
Disk space is full	`7`	Inno Setup
Reboot required	`8`	Inno Setup
Network failure	`101`	Prism installer (custom, reserved)
Package rejected during installation	`102`	Prism installer (custom, reserved)
Installation successful	`0`	Inno Setup
Miscellaneous install failure	`4`	Inno Setup

Duplicate values are rejected

Each scenario must carry its own value. 0/1/2/4/7/8 are already occupied by Inno Setup, so the three scenarios Inno has no dedicated code for — application already exists, network failure and package rejected during installation — use the custom codes 100, 101 and 102. Do not reuse an Inno code for a different scenario.

Reporting a custom exit code¶

Exit codes above the documented Inno range are reported by the installer script in prism.iss, so a caller can distinguish a scenario Inno itself does not encode. The [Code] section keeps the snapshot that decides the 100 case before the installation writes to the filesystem and to the registry, because CreateUninstallRegKey registers the application under

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Prism_is1

during the installation itself.

[Code]
var
  CustomErrorCode: Integer;        { 0 -> success; 101/102 reserved }
  WasPreviouslyInstalled: Boolean; { snapshot taken in InitializeSetup }

function DetectApplicationExists(): Boolean;
var
  S: String;
begin
  Result := RegQueryStringValue(
    HKLM,
    'SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Prism_is1',
    'DisplayName', S);
end;

function InitializeSetup(): Boolean;
begin
  { Take the snapshot BEFORE the installation registers the application. }
  WasPreviouslyInstalled := DetectApplicationExists();
  Result := True;
end;

function GetCustomSetupExitCode: Integer;
begin
  Result := CustomErrorCode;  { 0 -> Installation successful }
  if WasPreviouslyInstalled then
    Result := 100;            { Application already exists on the device }
end;

Notes on the implementation:

GetCustomSetupExitCode is called by Setup only when the exit code would otherwise be 0, so returning a non-zero value from it is the supported way to report a custom code on an otherwise successful run.
A process exit code on Windows is an unsigned 32-bit value: never set a negative code.
The Inno [Code] section is a single-pass Pascal script without forward references — every helper (DetectApplicationExists) must be defined before its first use, and comments inside the section use { } rather than the ; line-comment token, which is only valid outside [Code].
The uninstaller reports its own success with exit code 0 and any non-zero value as a failure; do not match a specific non-zero value.

Checking exit codes¶

Example session — a silent install followed by a check of the exit code:

PowerShellcmd

$p = Start-Process -FilePath .\prism-0.2.1-beta2-setup.exe `
    -ArgumentList @('/VERYSILENT', '/NORESTART', '/SUPPRESSMSGBOXES',
                    '/LOG=C:\prism-tests\install.log') `
    -Wait -PassThru
"exit code = $($p.ExitCode)"

prism-0.2.1-beta2-setup.exe /VERYSILENT /NORESTART /SUPPRESSMSGBOXES
echo exit code = %ERRORLEVEL%

The /LOG=<file> option writes an installation log that is useful when an exit code other than 0 has to be diagnosed; see Installation for the installer's other options.

Validated matrix¶

The matrix was exercised on the packaged installer in the Windows Server 2022 Vagrant VM (prismdefault), building prism-0.2.1-beta2-setup.exe with Inno Setup 6 / ISCC.exe and running it with /VERYSILENT /SUPPRESSMSGBOXES /NORESTART.

Scenario	Command run	Expected	Observed
Uninstaller, no arguments	`unins000.exe /VERYSILENT`	`0`	`0`
Fresh install (no earlier registration)	`prism-…-setup.exe /VERYSILENT`	`0`	`0`
Install over an existing installation	`prism-…-setup.exe /VERYSILENT`	`100`	`100`
Installation in progress (second instance)	second `Setup.exe` while one runs	`1`	unreachable — no `SetupMutex` in `prism.iss`
Disk space is full	install onto a filled volume	`7`	not exercised on the VM (probe-staged `PrepareToInstall` stop observed as `7` in the repro harness)
Reboot required	install requiring a restart	`8`	not exercised on the VM (probe-staged `PrepareToInstall` + `NeedsRestart` stop observed as `8` in the repro harness)
Cancel before installation	wizard, press Cancel	`2`	not exercised (needs interactive UI)

The 0 and 100 rows are confirmed by the VM run above; 7 and 8 are confirmed by probe .iss files derived from the shipping installer (the PrepareToInstall stop lane) in the repro harness. The 1 row is unreachable by construction — prism.iss wires no SetupMutex. The 2 row needs an interactive wizard the automated lane cannot stage, so its value is taken from Inno's documented exit-code range.

Related pages

Installation — how to install and verify the packaged installer · Releases — how the installer is built and published by CI.