Safe mode allows your antispyware/antivirus cleaning process to
be more efficient and effective as there will be minimal processes
running. If you scan while in the normal mode, some viruses or
spywares may not be deleted by the cleaning softwares if they are
running.
This is useful when you have a third party program which is causing
you to have problems starting up normally. You can simply boot into
safe mode and uninstall the problematic program.