PC Keeps timing out

I've got a problem with this one machine on the network,This times out a lot.I tjought it was because i was using hubs but I replaced the hubs with unmanaged switches but tis one machine still has the problem.what could be the likely cause of timing out.I have no problems with the other machines. Im going to try and replace the network card and see if something could change

Could be anything at this stage, we need to narrow it down a bit.
When you say the machine times out, do you mean on pings or in an application? And (assuming it is pings), do they time out to all destinations or just to certain ones on your network? And what proportion are lost (can't be all packets or it wouln't be working at all ).
It might be worth swapping the card as you suggest. You could also check for a speed/duplex mode mismatch between the card and your hub/switch, a cabling problem or perhaps even a misconfiguration at the switch.
Give us some nore info and let us know how it goes

must have been the network point, i've moved the pc to a different point and its now 10 mins and it hasn't timed out once,it was timming out every 30 - 45 secs previouly

Excellent

Nice Post, But is it possible to add a list of web sites that they can visit?,eg the company website

must have been the network point, i've moved the pc to a different point and its now 10 mins and it hasn't timed out once,it was timming out every 30 - 45 secs previouly

Would you care to further explain what you meant by *Timed Out*? It doesn't make any kind of Logical Sense to me how the issue was resolved just by placing your PC at a different location.

Is it possible to move your PC back to its original location and see if the problem still exists?