Safe mode is a boot option in the Windows boot menu. You can access the boot menu by pressing F8 immediately after the BIOS, when the Windows partition is booted.
Windows Installer will not work under Safe Mode, this means that programs cannot be installed or uninstalled in safe mode without giving a specific command using msiexec in command prompt. To make Windows Installer work under safe mode you need to create a registry entry for every type of safe mode you are logged in to, by running one of the following commands:
- Safe Mode:
REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\MSIServer" /VE /T REG_SZ /F /D "Service"
- Safe Mode with Networking. Type this in a command prompt:
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