Make Windows Installer work in Safe Mode
To make windows installer to work under safe mode you need to create a registry entry for every type of safe mode you are login into:
Safe Mode:
Type this in a command prompt and hit Enter:
REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\MSIServer" /VE /T REG_SZ /F /D "Service"
Then start the Windows Installer service by typing net start msiserver
Safe Mode with Network:
Type this in a command prompt and hit Enter:
REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\MSIServer" /VE /T REG_SZ /F /D "Service"
Then start the Windows Installer service by typing net start msiserver.