is it possible to end a task from window task manager using vb 6.0
if it is possible we could block end the internet explorer after a given time
I'd suggest you try some searches for keywords like "VB terminate task". You'll probably find it's not too difficult.
What do you mean by "block end"?
Will this be running on the server (as ansumansahu asked), or on the browsing PC(s)? And could you actually bring up the browser within your application? If so, check out the WebBrowser control. (Not that this is necessary, but it would be bound to simplify your control over the browser).