MaxRoms.com offers "portable" ROMs, which are pre-packaged downloads combining game files with pre-configured emulators for easy, immediate play on Windows PC. While convenient, downloading these .exe files carries higher security risks than using standalone, trusted emulators. Users should prioritize safety by employing robust browser protection, such as Google Chrome or Brave , and using ad blockers like uBlock Origin [1, 2].
In the context of "portable," you are likely looking for tools that run directly from a USB drive or a single folder without requiring a Windows installation: wwwmaxromscom portable
Here’s a good, concise review for focusing on their portable console ROMs (e.g., PSP, GBA, NDS, PS1, etc.): MaxRoms