You don't have to have a fixed IP address for any of them. The only one where it can make things a bit more handy is if you would set a fixed IP for the PC that runs the Slim Server - the others don't matter.
To set up fixed IP:
First you have to find out your current information:
Hit START button
Select RUN
In the box, type COMMAND (this gets you to a DOS command prompt)
At the DOS command propmpt type " IPCONFIG /ALL" (this will give you all the info you need about your network connection) Use this display to copy down your current IP address, your default gateway IP address, subnet mask, and DNS server IP addresses - you'll need them later.
When you're all done, type EXIT at the command prompt and the DOS session will close.
Now, to actually set the static IP address:
Select your network
Hit Properties Button
Select TCP/IP
Hit Properties Button
On the General Tab, select the radio button for "use the following IP address" instead of the "obtain IP automatically"
Type in the static IP you want (I usually use 192.168.1.201 - all my others are auto from 192.168.1.101 through 199 - 200+ is for static IPs) You can use anything from 192.168.1.2 through 192.168.1.255. By defualt, most home routers will start dishing out IPs starting at 192.168.1.100.
Type in the subnet mask (255.255.255.0 - 99.999999% of the time)
Type in default gateway (With an internal router, it should be 192.168.1.1)
Type in the DNS Server IPs (from first step) This is requried and becomes live when you request a static IP though it's in the section below in the same dialog box.
Hit OK.
You may need to reboot.
If this doesn't work for some reason, you can redo these steps but just go back and hit the "obtain IP automatically" radio button and say OK. That should undo everything you've done.
Bryan