How to uninstall previous version silently using NSIS script?

Question

I need to uninstall previous version if installed already. I have a NSIS script. Here is what I have tried:-

Function UninstallPreviousVersion
    ReadRegStr $R0 ${PRODUCT_UNINST_ROOT_KEY} "${PRODUCT_UNINST_KEY}" "DisplayName" 
    StrCmp $R0 "" done remove
    remove:
           DetailPrint "Removing previous installation."
           ExecWait '"$INSTDIR\uninst.exe" /S _?=$INSTDIR'
    done:
FunctionEnd

But When I run it instead of uninstalling old and install new version. it creates a new folder 'bin' under installation folder.

Any help please?

Answer 1

You might want to read the uninstall directory from the registry in case the old install location is not the same as $instdir but this is not your real problem. Your code does look correct so I suggest you do some "MessageBox debugging" in your uninstaller code...