I just want to know if there is any company can do this service for unmanaged dedicated server:
1- Checking and repair the system files
2- Checking the server configurations.
3- Checking the server Security.
There are many companies that can do this. Maybe put your request up as uuallan said, with some more exact requirements and maybe a budget. Finding people who do this in general is easy. Finding what you need for what you can afford is what you need.