APC PowerChute Business Edition Lost Connection

We are running SBS 2003 R2 with Exchange 2003, MS SQL 2005 Standard Edition and Symantec Antivirus Corporate Edition. Note that the MS SQL 2005 is not the one with workgroup which comes with SBS. This box works fine until people use it but surprisingly it gets freezed when left idle. I mean, when all clients log off of the server, after an hour if someone tries to connect the server, it says server is not responding.

We need to manually reset the server to make it fine again. I tried to find out the cause of the problem but dint got anything. We have sufficient HDD space left, also temporary folders seems ok, neither there is any service scheduled that runs when the server is idle. Then what is making server unresponsive in idle mode?

Please help.

We have been through this problem in past where our server was running with cheaper APC software and trend micro SMB as the antivirus. Anyways, as per your situation what I think is 1GB RAM is no way sufficient to run a system specially since you're running SQL. Most of us recommend that the max of 4 GB be installed when SQL is present.

Thank you very much for the help jigu902003. As you suggested, we changed the RAM chips and now successfully installed 4GB RAM on this SBS. Guess what, still the same problem. Still it freezes if left idle for an hour or more. It is also generating APC PCBE errors.

Now what?

HP Proliant ML350 G5 \ 2 GB RAM \ SBS2003
SQL2000
Kasper sky virus scan
I want to know how you can resolve this issue.

That makes some sense but what if the problem is related to PowerChute? Anyways, I would like to know if there is anything reported in the system or application logs ?

Provide advice and support APC, remove the USB cable. And he told me that. Batteries deteriorate, I open the server without going through UPS. but we tend to find the server quite slow and on occasions have noticed the server CPU to be at 100% for several minutes. I look at the Processes not how it works more than 50%.

which one is critical? then I can start to fix them from that.