I have a W2003SBS machine SP2 that I recently added Red Gate email archive server for our exchange server. 4 days after the install the network slowed to a crawl. I think the Red Gate install is coincidental but am putting this in for clarity.
The machine has always had some form of gremlin in it (over the past 5 years) in that certain things have been slow and quirky over the network (all 6 PCs are still XP). The server runs Arcserve and Trendmicro WFBS and is file and printer sharing. We had a very bad experience with Symantec about 4 years ago when they first introduced their end point protection. Symantec was deinstalled but I believe it may have done some damage to the server. We had to disable "Indexing Service" after removing Symantec as that would cause the CPU to go to 100% and make the network crawl.
The symptoms are the server just stops responding . Task manager also stops responding (it shows 2% cpu utilization) when it is responding. This seems like hardware to me. I am putting on HP's latest drivers for the G2 (bios, chipset, LAN, SATA Controller firmware and driver). I am also defrag'ing the drives as they are badly fragmented. I had all users shut their machines down and at that time the server started behaving better (much more responsive)
Given past issues and what is occurring right this minute I am thinking there is some bad interaction with the SATA RAID5 (board level not OS) and Win2003. I am also concerned that it could be LAN related with a gigabit switch and older wiring. Everything shows good on the link lights on the switch but I am still looking that direction also. We are replacing the gigabit switch with a new one. If necessary, we will redo wiring. I am looking more at the hard drives though.
No one is logged into the server at this time and it is still going in stop and go fashion. I am trying not to do a clean server install but have it on the list if I can't resolve this fairly quickly.
No event log errors that state hard drive errors. It almost seems to me as I watch each slow down occurrence that the longer the hard drive is worked used the more the slowness occurs. When I boot the server it is fast as it should be - it just works. The slowness creeps in over a period of time.
I am working on the initial remediations but am hopeful going to get a reply that says do a 30 second update against a driver and it will fix your issue...if not, I am looking for other courses of action.