I have been trying to fix this problem for a few weeks now, and none of the solutions I have found so far have helped. This is like a last resort for me, everyone seems to have different solutions but NONE of them have worked for me. Whenever I run hamachi.msi I just get an error saying "There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor." I have tried downloading the installer from other websites, on different browsers, uninstalling hamachi (Which gives the same error), clearing my temp, allowing full access to all users to temp, and trying to launch the MSI through CMD with run as administrator. Nothing works. I am on windows 8.1 and would appreciate any help, this is driving me crazy.
This seems to be a problem with Windows rather than Hamachi.
You should check this link, it might solve your issue.
I wasn't able to find a solution on that specific page, but now I know to stop checking hamachi and start checking other sites for solutions. Hopefully your tip will lead me to a solution. Thank you.