Hi all,

For the past few months I'm experiencing reoccurring problem at one of my client's site.
there is one station (dual core/2gb/128gb ssd/win 7 x32)that works on an sql database that is located on the office file server (sempron 3400/2gb/xp pro).
All of the office computers (about 12 computers and 4 network printers) are connected to a 24 ports hub and dlink 2670U adsl router.
every few days there is a disconnection on the workstation i mentioned.
I tried :
1. reinstalling windows on the WS (few months ago - because of a virus)
2. added a NON ON BOARD network card (like a year ago)
3. replaced the network cable that goes to the router
4. Added a router for internal network to seperate it from ADSL router (just few days ago)

When I replaced the network cable that goes to the router, The computer worked stable for few days, But few days ago disconnections returned.
I installed ping monitor software over the weekend (After adding a router), And result were good (maybe 20 pings dropped out of 200000 pings, But this morning it disconnected again from the network (There was no ping to router AND to ADSL router at the same time).
I suspect it might be the network card, Or something to do with the SQL database (The computer OR the server keeps working after the disconnection and the server still has internet).I have this intel pro network card I kept for some time and i considered to put it in the specific WS.
What would you suggest ?
Thank you