What you should keep in mind is that the server itself doesn't have to be really powerful. In general, a file server (4 PCs connected to it) can run on just a Pentium. In many examples. I've seen people use a 486 (haha, before I was born) coupled up with adequate ram and a HD to accomodate the house (house server). Easily, you can just go and buy a refurbished, lets say, Pentium 3, and put as much RAM as you'd like (Files I'd say should have adequately over 32 MBs), and good old big HD. Good PSUs for reliability would do some good too.
However, in another case, after reading a bit, 4 PCs connected to it. In that case, I'm kind of assuming that you may be setting it up and the gateway:
PC1----
PC2------ Server
PC3------
PC4-----
To do this, you need atleast 2 NIC cards. NICs are cards with ethernet? One is connected to the modem, or way to the internet, and one is connected to the switch to which is connected to the PCs.
Server --> Switch -> PC1/2/3/4
In the first example, you'd need however, 5 NIC cards (probably over the PCI slot limit of the ancient motherboard, or current days).
1 for modem, 4 for PCs. This would probably be impractical.
Again, to start, you'd need to do some research on what you want your server to serve as. You need to know the goal to know you need to do. The more the server does, the more horsepower your server needs.
1) Research
2) "
3) Money
4) PC to act as a server
5) Lots of ehternet cable
6) Hub/Switch
7) Tying everything together
8) Small details - (ie. OSes to be used, upgrades to the server, security, etc)
9) You'll know more than me by the time you get to this step =DDDD.
10) Good luck!!
While doing anything, keep your common goal in mind. Remember, overkill is fine only if you have the money to spare!
Agreed... Keep again in mind that, simple file servers don't require high specs. Instead, actually, low ends are better fitted to do the job, as they usually run on less electricity, generate (generally) less heat, and cost cheap to buy in the first place.
(ex. This guy said he owned a 386 (that's what they're called, right?), and with a high capacity HD (I believe it was 500GBs or something), the CPU usage never surpassed 30%)
Indeed, fab. processes were larger back then; however, the TDP is still lower, as the speeds were lower. The increase in clock speeds weren't proportional to decreases in fabrication process.