Networking

There is a company called Grid4, they sell T1 service and telephone service.  At our office, we have 4 PC's  and 1 printer and one WiFi access point.  The connectivity is horrible in terms of internet access.    Example e.g.   Ping 216.11.111.1 -t  returns 3 digit MS time and drops packets about every 4 or 8 pings, at time 2 drops in a row.  At first we thought a workstation was maybe throwing out a bunch of garbage.  In fact Grid4 says the workstations are "calling Microsoft."  We did check and know that there are many FAILED updates.  However we do not think that the workstation(s) are trying so hard all day long to get updates that the T1 line is saturated.  When we turn off ALL workstation, unplug the Wireless AP, and plug a single workstation into the AdTran (a switch), the results are the same, dropped packets and triple digit mili seconds on the returns.   The service provider has indicated that from inside the switch pinging out to the same IP  216.11.111.1 they also get triple digit reply's and dropping packets every now and then.  

What could be the problem?  We think it's the Adtran or the circuit that needs attention.  When Grid4 sends their tech out he just says, it's your network.  And that they workstations are talking to MS and causing a jam of sorts.      We do know the workstations need maintenance (patches and clean up) however the symptoms are the same with them turned off.