No Internet Yellow triangle on icon

No connection wired or wireless. Uninstalled/updated drivers- no good.
Installed 'Tenda' adapter still nothing, although no wired connection should have told me that.
removed security from SSID - again no wired should have alerted me to it being not wireless related!
Ran a 'Ping'- in CMD typed ping 192.168.1.254 -that is 'ping' space 192...
returned: no packets sent, on working pc returned packets sent=4 recieved =4 lost=0

Vodafone said 'software issue' 

uninstalled McAfee turned off firewall - it worked. 

Still Not Working, try this too.
Software Firewalls.
Make sure that the Software Firewall on each computer allows free local traffic. If you use 3rd party Firewall Windows Firewall has to be Off, and the active Firewall has to adjusted to your Network IP numbers on what is some time called the Trusted Zone (consult your 3rd Party Firewall instructions

General example,  http://www.ezlan.net/faq#trusted

Please Note that some 3rd party Software Firewalls keep blocking aspects of Local Traffic even it they are turned Off (disabled). If possible configure the Firewall correctly, or totally uninstall it to allow clean flow of local network traffic. If the 3rd party software is uninstalled or disables, make sure that Windows native Firewall is On .
If you Uninstalled any of the applications mentioned above do this.
Reset the Network Stacks .
Type Cmd in the Start Search text box.

Press Ctrl-Shift-Enter keyboard shortcut to run a  Command Prompt as an Administrator.  Allow elevation.

Type netsh winsock reset in the Command Prompt , and then press the Enter key.

Do the same process for refreshing the TCP/IP, just replace the typed command with.

netsh int ip reset
Restart the computer.