PC's crashing on network

[paul.rowling]

Hi,

I have been to see a network comprised of 5 pc's and a dell server running Microsoft Small Business Server 2003. All the pc's are joined to the domain and users login via domain logon accounts. The users use the server to file serve Autocad files and that's pretty much it. At approximately the same time every day (4:00pm - 5:00pm) all pc's run very slowly and then stop responding. The network drives mapped on the pc's to the server also loose their connection. After a reboot of the pc, everything is then OK. Even when thigs are running OK, If I view network places on a pc, it is completely blank.
There are no viruses or spyware on any of the pc's, when the machines do crash, If you look in Task manager (when it eventually opens) the majority of programs are Not Responding. What's interesting is that this only seems to effect those pc's which are running AutoCad at the time, and what's more interesting is that if you try and save the autocad drawing back to the server when they do crash, you can't because the network drive loses it's connection. There are no obvious scheduled tasks that run on the server at this time either.
I initially suspected network hardware to be at fault but the customer has said that the router has since been changed yet the problem still occurs.
This is a really strange fault which I just can't work out. I have checked the domain users accounts and there are no restrictions or "logon hours" restrictions.

Any help would be greatly appreciated.

Best Regards

Paul Rowling

[Guts3d]

Is there an anti-virus scan sceduled at that time?

[paul.rowling]

Hi,

No, unfortunately there isn't a virus scan scheduled at that time.

Cheers

Paul

[Archangel42069]

I take it everybody is shutting down for the day around 4-5pm? Could it simply be the load of 5 users all trying to save their massive AutoCAD files to the server at the same time? Perhaps not a load on the server, but on the router? What kind of router are they using?

[se7en]

You could just watch the server itself around that time and see what processes are runing, and what is using the most utilization.

[paul.rowling]

Hi,

No I don't think it is caused by users logging off as they don't finish until 6pm, plus the last couple of weeks there has only been two employees working. The roiuter is a Netgear model with built in ADSL modem, unfortunately I don't know the exact model off the top of my head.

Many Thanks

Paul

[NooNoo]

If it is providing dhcp, it might be when it renews the lease... the router I mean.

[paul.rowling]

Mmmmmm, interesting NooNoo, however there are 2 pc's that are constantly left on and these are unaffected when the other machines crash. I'll definately check it though.

Cheers

Paul

[Garak]

Is it possible that both the router and the server are trying to dish out IP addresses?I have no idea weather DHCP has been turned off on the server or the router.... could be worth a shot?

[paul.rowling]

Hi,

Yes, I had wondered about this Garak, because I know for sure that the router is acting as a DHCP server. I need to check the Windows Server to see if this is also acting as a DHCP server. I'll let you know how I get on. By the way I think I need pointing in the right place to find how to turn off DHCP in Microsoft Small Business Server 2003.

Thanks

Paul