Network of 5 PCs - Connection Issues

My friend describes his connection issues as follows. If anyone can suggest
anything, it would be appreciated:

Hello,
I have 5 computers which are set up in my network
Somehow yesterday I could not access from one computer to another on all
computers in the network. I have computers named Sys1, Sys2, Sys 3 , Sys4 and
Sys5. My problems starting with Sys1



Sys 1 After clicking on my computer under Network drives I only see

drivec on Sys 3 and drivec on Sys 5

drivec on Sys 2 and drive on Sys 4 do not show up any more so I can not
access those computers from the network from Sys 1



Sys 2 is correct, After clicking on my computer under Network drives I see
and can access Sys 1, Sys 3, Sys 4, and Sys 5, which are all the other
computers in the network.



Sys 3 After clicking on my computer under Network drives I see

drivec on Sys 1 , drivec on Sys 2 drivec on Sys 4 and drivec on Sys 5

I can acess all other computers on the network except for drivec Sys 2

drivec Sys 2 shows up but has a red X through it. When I click on it

a window pops up saying, “An error occurred while reconnecting to drive Sys 2

Microsoft windows network. The network path was not found.



Sys 4 all is correct, can access all other computers on network.



Sys 5 After clicking on my computer under Network drives I see

drivec on Sys 1 , drivec on Sys 2 drivec on Sys 3 and drivec Sys 4, which is
all other computers on network.

However when I click on drive Sys 2, a window pops up saying, “An error
occurred while reconnecting to drive Sys 2

Microsoft windows network. The network path was not found. Unlike Sys 3
there was no red X through Sys 2



System OS as follows
Sys1=Window 2000
Sys2=XP Pro
Sys3=Windows 2000
Sys4=Windows 2000
Sys5= XP PRo

Thanks for your help