从批处理文件执行时 MSI 安装程序不安装

Question

I am currently creating an improvised installer for a cople software packages. To do this I have to install a couple MSI packages first before doing a couple file operations.

To install an MSI package I am using the following command:

start /wait msiexec /i "Myinstaller V2.1.msi" /qb

This command works and installs the package instantly and witout any problems via CMD.

But when I put this command in my batch file and execute it as an administrator, I get the following error: This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package

What cold be the problem? Using the same command via the console works flawlessly, only the batch file throws the error...

EDIT: I have also tried the /a parameter in order to install it as an administrator and it does not work either. Full command in batch file:

start /wait msiexec /qn /a "Myinstaller V2.1.msi"

EDIT2: I just realized that it only does not work when I start the batch file with Right click > Run as administrator When I open a console with administrative rights and start my batch file it works for some reason...

Is there a way to make it work with the Right click > Run as administrator method?

SOLUTION: Thanks to RGuggisberg's answer I now know that the directory changes once the file is executed as an administrator . With a small change the installer gets fired up as an admin and works perfectly starting the installer from a relative path in the same directory:

@echo off
pushd %~dp0
start /wait msiexec /i "Myinstaller V2.1.msi" /qb
pause

I've now also implemented a feature to detect wether or not the installation fails or not:

@echo off
pushd %~dp0
start /wait msiexec /i "Myinstaller V2.1.msi" /qb
if %ERRORLEVEL% EQU 0 echo SUCCESSFULL 
if NOT %ERRORLEVEL% EQU 0 echo MyProgram installation FAILED
pause

Answer 1

The current directory changes when you run as administrator. If you want to prove that to yourself, see this post Difference between "%~dp0" and ".\"? Include the full path to your filename and it will work.