I understand you set-up a _new_ ePO 4.5 on a _new_ Windows 2003 server !?
Did you check the network connectivity ?
Is it possible some firewall (possibly Windows FW) is preventing incoming communication from the agents to the server ?
Can you ping the server from the agents ?
On the (test) agents, can you check SiteList.xml and ServerSiteList.xml and control what name & IP the agent is trying to reach ?
as for the client error message I found a KB article (https://kc.mcafee.com/corporate/index?page=content&id=KB60506&actp=search&viewlo cale=en_US&searchid=1283411285546) which has a good explanation that practically the code -88 is masking the actual error (which might be due to problems using the proxy on client).
Please check if the test clients actually wants to use the new ePO server (e.g. via browser log http://hostname:8081)
/As for the other error: does it still recur?/
Thanks for your response to my question. The problem have been rectified. It was my apache ssl cert broken which caused the agent cannot communicate with the EPO server. After I re-created new ssl cert, the agent able to communicate with the EPO server. Problem resolved. Thanks a lot.