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: 
This is similar to Elektrostudios' answer, and is what worked for me:

```
    Filename: {cmd}; Parameters: "/C Mkdir ""{app}\Uninstallers\{#MyAppName}"""; Flags: RunHidden WaitUntilTerminated
    Filename: {cmd}; Parameters: "/C Move ""{app}\unins000.exe"" ""{app}\Uninstallers\{#MyAppName} - uninstall.exe"""; StatusMsg: Installing {#MyAppName}...; Flags: RunHidden WaitUntilTerminated
    Filename: {cmd}; Parameters: "/C Move ""{app}\unins000.dat"" ""{app}\Uninstallers\{#MyAppName} - uninstall.dat"""; StatusMsg: Installing {#MyAppName}...; Flags: RunHidden WaitUntilTerminated
    Filename: {cmd}; Parameters: "/C Move ""{app}\unins000.msg"" ""{app}\Uninstallers\{#MyAppName} - uninstall.msg"""; StatusMsg: Installing {#MyAppName}...; Flags: RunHidden WaitUntilTerminated
    Filename: REG.exe; Parameters: "ADD ""HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Windows 8 ContextMenu - {#MyAppName}_is1"" /V ""UninstallString"" /T ""REG_SZ"" /D ""\""{app}\Uninstallers\{#MyAppName} - uninstall.exe\"""" /F"; StatusMsg: Installing {#MyAppName}...; Flags: RunHidden WaitUntilTerminated
    Filename: REG.exe; Parameters: "ADD ""HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Windows 8 ContextMenu - {#MyAppName}_is1"" /V ""QuietUninstallString"" /T ""REG_SZ"" /D ""\""{app}\Uninstallers\{#MyAppName} - uninstall.exe\"" /SILENT"" /F"; StatusMsg: Installing {#MyAppName}...; Flags: RunHidden WaitUntilTerminated

```

Using Windows 7, I discovered that the "Move" command wouldn't work unless I had somewhere to move the files to first, meaning that I had to add the mkdir line at the top. Also, the uninstaller wouldn't work without the .msg file moved as well, so I followed the pattern and added that line too.

I didn't bother to change "Windows 8" to "Windows 7" but it didn't make any difference, so I'm leaving it alone. If there's a problem with that I'm unaware of, I'm sure someone will indicate such in a comment.

{#MyAppName} is, of course, the constant defined at the top of the ISS file declaring the name of the application. Your constant may be defined differently, so you'll need to change it to match where necessary.
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.