Auto-uninstall old before installing new: Difference between revisions
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This is a code snippet you can put into your .onInit function that will detect whether your software is already installed and, if so, allows the user to uninstall it first. | This is a code snippet you can put into your .onInit function that will detect whether your software is already installed and, if so, allows the user to uninstall it first. | ||
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[[ | [[Category:Windows Shell Integration Functions]] | ||
Revision as of 11:29, 24 June 2005
| Author: codehistorian (talk, contrib) |
This is a code snippet you can put into your .onInit function that will detect whether your software is already installed and, if so, allows the user to uninstall it first.
In the source below, we use the define ${PROGRAM_NAME} to be the name of the product as well as the name of the installer/uninstaller. You can either define this define or search/replace it. If you name your uninstaller or registry location differently, you should change those strings accordingly.
Function .onInit ReadRegStr $R0 HKLM \ "Software\Microsoft\Windows\CurrentVersion\Uninstall\${PROGRAM_NAME}" \ "UninstallString" StrCmp $R0 "" done MessageBox MB_OKCANCEL|MB_ICONEXCLAMATION \ "${PROGRAM_NAME} is already installed. $\n$\nClick `OK` to remove the \ previous version or `Cancel` to cancel this upgrade." \ IDOK uninst Abort ;Run the uninstaller uninst: ClearErrors ExecWait '$R0 _?=$INSTDIR' ;Do not copy the uninstaller to a temp file IfErrors no_remove_uninstaller ;You can either use Delete /REBOOTOK in the uninstaller or add some code ;here to remove to remove the uninstaller. Use a registry key to check ;whether the user has chosen to uninstall. If you are using an uninstaller ;components page, make sure all sections are uninstalled. no_remove_uninstaller: done: FunctionEnd
