I'm creating an installer for my Visual FoxPro application using ISTool and Inno Setup. It is ok for me for the first time. But, I updated my code and re-built the EXE file. Then, compiled the installer again. I found that my update was not compiled into the installer and I did not see the update in my running application.

I noticed that the EXE file, which was built by VFP, was updated properly. It seems the installation script did not output the updated file. But, when I changed folder names, it did work. I don't want to change folder names whenever I run that installation script. It is not a good idea actually.
I think it is because of Windows 7 cache system. Mine is Windows 7 Home Premium Service Pack 1.

For example,
My previous output file is located at C:\path\to\myinstaller.exe
When I compile the installation script, the output file there should be overwritten, but it was not as expected. Although I deleted the file, it did not work.
When I changed to output file path as C:\newpath\to\myinstaller.exe, I got the fix, but it is not a solution what I'm looking for.

Does anyone how to do that?

[Edit]
I found that the installed directory was not updated properly.
For example, I installed the program to C:\Program files\MyInstalledApp
When I run the installer again, that installation directory should be overwritten, but failed.
Thus, I got to uninstall the app before I re-install it.

Is there any fix for this?