- Another solution -
Overview
Manually delete the Hamachi2Svc service as the local administrator.
Detailed
I was experiencing the same problem trying to reinstall a Hamachi installation that had become corrupted during a Windows 7 -> Windows 10 upgrade. Changing privileges on the C:\Users\%USERNAME%\AppData\Local\Temp directory had no effect. The installer kept telling me it had found a previous version of Hamachi on the computer, prompting me to update, but the installer failied with the DLL error everytime.
I performed a manual uninstall of the program, stopping the service, uninstalling Hamachi from the Device Manager, deleting the Hamachi.sys driver, all the Hamachi directories and all the main Hamachi registry entries but the installer was still failing with the same message. Only after I manually deleted the Hamachi2Svc service was the problem resolved, allowing me to install successfully. I believe the default account running the service may have been changed in the past, causing this issue.
Steps as delete the Hamachi service:
- Open the Start menu, click the Search/Run box, type cmd then press CTRL + SHIFT + ENTER (this runs the command prompt as the local administrator account).
- Type sc stop Hamachi2Svc and hit enter (stops the service).
- Type sc delete Hamachi2Svc and hit enter (deletes the service).
Hopefully you will no be able to re-install Hamachi, unless something else is causing the issue.
Any further issues could be caused by restricted access or data corruption to directories and/or registry keys, so you will sometimes need to 'take ownership' of said directories/registry keys in order to delete them, assuming no physical disk corruption.