Operating system is essential to operate computers. Normally, computers come with preloaded operating systems. However, often the preloaded operating systems are not able to fulfill all requirements of users. The users sometimes need to change the operating system based on their needs. Although some comparative studies and tools are available on operating systems, there is still a lack of tools that provide independent and objective review and recommendation to help the users understand and select from all major operating systems. This paper propose a tool called FSOS, which analyses well-known operating systems used at domestic, commercial and industrial level and suggest suitable operating systems to the users as per their requirements.