Sorry for the delay I needed to research log files from source control to see when and why we removed the backup folder. The decision to delete the backup folder was done in 2013 when we changed the company name. The installer had issues with uninstalling from the previous install directory to a new directory. A backup folder with information that was no longer useable was created and eventually restored when the end user rebooted. The end user was never alerted to reboot so an unusable install directory had large files in a backup folder that were never going to be used or needed. This prevented the folder from being removed completely like an uninstall should have done., When the end user eventually did restart these files would be put back into the old install directory and stay there forever or until the end user manually deleted them. Additional issues thou similar to the above issue. If the end user simply decided to uninstall product and not reinstall it. The backup folder was created with install files that were no longer needed. Same result the end users did not like the files being left behind that were not being used. Nor would I. The final issue is also related to the first but caused many more issues. If the end user upgraded the product it would also create a backup folder. This backup folder would get bigger and bigger because the end user was never told to reboot. 3-6 months later they would reboot and the backup folder would put the old files back into place while leaving many of the new files. This caused many issues. Restoring 3-6 month old files that were no longer compatible not to mention files that may or may not even be useable. At one point we had multiple versions Infragistics DLL’s and other version specific DLL’s. Simply uninstalling the product would not clean up the issue because the uninstall was not aware all of these files were in the install directory. Looking back if we had known we were installing the Infragistics files multiple times some of these issues may have been resolved. Hard to really say that was almost 7 years ago.

I don’t believe previous install directory has ever worked correctly for us. If the product is currently installed in directory A and we want to install to directory B. The uninstall does nothing to directory A but it does install correctly to directory B. Not sure why that is or what is wrong with the script. I am open to any suggestions to improve our install script.

I added Infragistics*.* to the exclude, removed the backup delete line, and the WOW registry edits. This appears to have fixed our issue. Hard to say until it goes live but I no longer have the issues on our QA machines.

Is there a way we can see which files are being installed multiple times?
Is it as simple as reviewing the uninstall log?