Question : network slows down every afternoon

hi im running SBS 2003 with exchange and symantec mail security for exchange installed among some other programs.
My server runs everything DNS, DHCP, file and print, etc
I have 10 users and my server is a Xeon CPU 3.06g with 512MB.

Basically my issue is that every afternoon access to the server seems to be extremely slow.  Users browsing the network and accessing data files are complaning that it is terribly slow and always around late afternoon.  Some users it happens to them one day and then someone else the next.

The server is running about 80 processes and CPU usuage ranges all the time as it should i suppose.

I have looked into scheduled tasks and times it updates and things like that.  nothing runs in the afternoon.

Is this server spec'd high enough to run all these tasks and users.  Could an increase in RAM be a quick fix?

How can i pinpoint what seems to be slowing things up in the afternoon.  

I have checked all computers for viruses/ spyware and adware

thankyou

Answer : network slows down every afternoon

Well, that wasn't a COMPLETE IPCONFIG /ALL as requested, I am looking for your COMPLETE Networking configuration.  

What little you provided shows that you have misconfigured your DNS Server IP's which should ONLY be that of your server, 192.168.200.1 (on both your server and the workstations), as stated above.

Also, it looks as though you are using your router for DHCP.  While this is doable... generally it results in misconfigurations for the workstations... which in this case doesn't seem to be passing along the WINS server IP.  I'd suggest that you disable DHCP on your router and let it run from the SBS.  See the bottom of http://sbsurl.com/dhcp for info on how to do this.

See http://sbsurl.com/msicw for a complete network configuration overview.

Jeff
TechSoEasy