Windows 7 Ultimate x64 Windows Installer 5.0.7600.16385 View attachment 4537 Hello everyone, I just joined this forum in desperate need for a solution. I recently started receiving this error message whenever I try to install a *.msi program. I have tried every single fix I've found on the net with no luck, these include: - Unregistering/registering msiexec (in normal and safe mode) - Exporting [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msiserver] registry value from a working OS and import it in mine. - Copying MSI files (such as msiexec.exe, msi.dll, msisip.dll and others) from other Windows 7 OS and replacing them with mine. - System restore to a previous point. And many others I don't remember right now. Unfortunately there's no Windows Installer 5.0 available to download and try reinstallation. Reinstalling the OS isn't really an alternative right now. I attached my [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msiserver] key in case someone wishes to analyze it. I would greatly appreciate any other suggestion. Thanks in advance! P.S.: Any additional information you need just ask for it, I will provide it as soon as possible.