How to control our worker to stop working on internet without using proxy or lansetting in there system?

Answer 1

Disable NAT to that computer by blocking it at the proxy server using a firewall tool such as shorewall and blocking everything except the proxy port and maybe ports 1-1024. You can also setup Group Policy and change their account level access to "Users" (Go into Start -> Control Panel -> Adminstrative Tools and choosing "Computer Management". In there you will see "Users and Groups". Choose their name and choose properties. Go into their "Groups" tab. Add "Users" and delete all others) if they have Windows XP. This will allow you to force a proxy setting. You can learn more by doing a Yahoo search on:
"Shorewall" and
"Enable Group Policy in Windows XP"

Answer 2

you might try a chair and whip or send the lion in, in your place! you might try putting the message "caught you" on their screens when you detect them useing the wrong protocalls, or a simulated security crash scenario on their computer followed by stiff warnings. with diciplinary procedures for repeated events. in any event keep a log of the events when evaluations come up. it could have a sobering influence during an evaluation or a possible consideration for raising a salary

Answer 3

Most routers have simple to use settings just for this purpose. Check you instruction manual.