If you just need the content of a FrontPage .htm file, open it in Notepad++ or drag it into a modern browser (Chrome/Edge) to copy the visible text.
A portable application runs directly from a USB drive or a folder without needing to be "installed" into the Windows Registry. For a complex tool like FrontPage 2003 (which relies on COM objects and deep Windows integration), creating a truly portable version is technically challenging. Most "portable" versions available on forums or download sites are actually hacked or repackaged copies. microsoft frontpage 2003 portable download link
If you own a legitimate license key, you can install the full version of FrontPage 2003 on Windows 10 by using a virtual machine (e.g., VirtualBox running Windows XP). It does not run reliably on 64-bit Windows 10/11 natively. If you just need the content of a FrontPage