Good day \r\n\r\nI have a small network setup in my office.\r\n\r\nWe have internet connection connected to TP Link (150M Wireless Lite N Router Model No. TL-WR740N / TL-WR740ND ) in its WAN \r\n\r\nport. This is connected to TP Link (300M Wireless N Gigabit Router Model No. TL-WR1043ND) configured as Access Point. \r\n\r\n-\-\-\-\-\-\-\-\-\-\-\-\-\r\nSettings:\r\n-\-\-\-\-\-\-\-\-\-\-\-\r\n[LIST]\r\n[*]TP Link WR740N (Main Router): LAN IP: 172.16.5.2, DHCP: disabled, Wireless: Disabled\r\n[*]TP Link 1043ND (Cofigured as Access Point -AP): LAN IP: 172.16.5.1 DHCP: Enabled, Wireless: Enabled.\r\n[/LIST]\r\n\r\nWe have 10 PCs (including one HP Server with Win2008 R2), one Seagate NAS Server and 1 Mac Air book laptop all part of a \r\n\r\nlocal domain.\r\n\r\n1) Win2008 Server and NAS plus two PCs are connected to Main Router through wired cable\r\n\r\n2) Mac Laptop and another two PCs are connected to AP wirelessly.\r\n\r\n3) AP is connected to two Zyxel Switches which in turn provides connectivity to two sets of 03 PC in each one of them.\r\n\r\nAbove is the brief description of setup.\r\n\r\nProblem is: For last two weeks, my boss owning the Mac Laptop is not able to work properly. Every now and then his system \r\n\r\nbecomes hanged. (While in home he is not facing any issue). \r\n\r\nI tried the diagnosis with process of elimination:\r\ni) Is there issue with some of systems connected directly to Main Router\r\nRem: I think not, otherwise other PCs would have the same problem.\r\n\r\nii) Is it because wireless connection?\r\nRem: The two PCs connected to AP are working perfectly.\r\n\r\niii) Is it because of Mac OS - Windows compatibility?\r\nRem: Again, had this been the case, the problem would have come up in the first instant. We have this networking setup since \r\n\r\nlast six months. No issue till 01 Jan 2015!!!\r\n\r\niv) Is it because of some software update?\r\nRem: As part of policy, unless absolutely necessary, updates for all computers including Mac is disabled.\r\n\r\nv) Could this be a domain problem?\r\nRem: Again, all was working till last date of 2014!\r\n\r\nSome people advised me to change MTU of his wi-fi settings. Did that but no results. Changed the AP Wireless Channel from auto to 6. No result.\r\n\r\nCan anyone help?