Is there a need to reconfigure my server?

Hello everyone, I have setup a network server at my home that connects directly to the internet. I have also made only one system for all data. This is for running 3 users that are remote and 2-3 other users. I wanted to know that in such a setup if anyone could hack into the server? Also is only one system OK to handle all the information or is it necessary to have 2-3 systems. I have done what a typical home sever is like. Is there any possibility of losing any of my data? So, the ultimate question is there a need to reconfigure my server?

I have seen a problem in the computers which are used in the DMZ. It has sharing of files and anonymous FTP enabled. Both these options do not allow anyone access to the drive and also do not allow write access to any of the drives. But, I recommend you to disable both these options. There is no other need to reconfigure your server, except these options. Everything else will work actually fine as I have the kind of setup too.

There is absolutely no need to reconfigure your server setup. I have the same kind of setup and I tried to gain access into my server system via FTP, but I was denied access. The way I tried is shown below, you can also try this and check your server security:
$ ftp 24.121.67.194
Connected to 24.121.67.194
220 Microsoft FTP Service
Name (24.121.67.194:spyguy): anonymous
331 Anonymous access allowed, send identity (e-mail name) as password.
Password:
230 Anonymous user logged in.
Remote system type is Windows_XP_SP2.
ftp> dir
227 Entering Passive Mode (24,121,67,194,19,142).
125 Data connection already open; Transfer starting.
226 Transfer complete.
ftp> put junk
local: junk remote: junk
227 Entering Passive Mode (24,121,67,194,19,142).
550 junk: Access is denied.
ftp> quit

I havnt got any idea about setting up servers. I think you must reconfigure your server because in a usual setup there are mostly more than one computer on which the information has to be kept. There must not be a direct connection to the internet. Rather than that there must be an encrypting software or a firewall that protects the information within.