Question: I need to install a couple of installers in the same directory so it conflicts with the Inno Setup uninstaller name `unins000.exe` and `unins000.dat`

Is there a way to change the default name of an Inno Setup uninstaller?

Answer: 
Well, while it's still not possibly to nativelly change the uninstaller name then I'll use Batch commands at the run section to rename the uninstaller and to do the same in the uninstaller registry paths:

```
[Run]
Filename: {cmd}; Parameters: "/C Move ""{app}\unins000.exe"" ""{app}\Uninstallers\{#ApplicationName} - uninstall.exe"""; StatusMsg: Installing {#ApplicationName}...; Flags: RunHidden WaitUntilTerminated
Filename: {cmd}; Parameters: "/C Move ""{app}\unins000.dat"" ""{app}\Uninstallers\{#ApplicationName} - uninstall.dat"""; StatusMsg: Installing {#ApplicationName}...; Flags: RunHidden WaitUntilTerminated

Filename: REG.exe; Parameters: "ADD ""HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Windows 8 ContextMenu - {#ApplicationName}_is1"" /V ""UninstallString"" /T ""REG_SZ"" /D ""\""{app}\Uninstallers\{#ApplicationName} - uninstall.exe\"""" /F"; StatusMsg: Installing {#ApplicationName}...; Flags: RunHidden WaitUntilTerminated
Filename: REG.exe; Parameters: "ADD ""HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Windows 8 ContextMenu - {#ApplicationName}_is1"" /V ""QuietUninstallString"" /T ""REG_SZ"" /D ""\""{app}\Uninstallers\{#ApplicationName} - uninstall.exe\"" /SILENT"" /F"; StatusMsg: Installing {#TipName}...; Flags: RunHidden WaitUntilTerminated

```
Inno Setup does not offer any way to let you name (or rename) the uninstaller. Inno Setup takes care of naming conflicts on its own.

Also note that when you try to rename the uninstaller manually (like some answers here do), you break the reference to the uninstaller in *Add or remote application* in Control Panel. 

Even if you fix the reference, there's another problem. When you upgrade later, the new installer won't find logs of the previous installer and won't be able to merge them. Consequently a future uninstallation won't completely remove the application. See the [Appending to Existing Uninstall Logs](https://jrsoftware.org/ishelp/index.php?topic=appendnotes) in Inno Setup documentation.