Office 2019 requires a legitimate product key. Portable versions usually include a crack (KMS emulator, AutoKMS, or patched .dll files). Windows Defender and most antivirus software will immediately quarantine these files as or HackTool:Win32/AutoKMS . While some users argue this is a "false positive," it is a risk you must accept.
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Portable applications are software programs that can be run from a portable storage device, such as a USB drive, without requiring installation on the host computer. These applications are useful for users who need to work on multiple computers or in environments where software installation is restricted. Office 2019 requires a legitimate product key