Windows 9x does not have the features a webserver needs. There is no stability, memory management is horrible, and the FAT32 file system will crumble. On a machine like that, for a non-professional webserver, linux or a BSD would be the perfect choice. No need to pirate anything, no need for expensive licenses, and you have a proven system (with over 20 years of history 😀). It may take a little longer to learn, but it looks good on a resume. 😉