in our college computers are connected by lan how to send a file from one computer to other?

Answer 1

Sharing privileges need to be properly enabled & configured .... requires administrator login to do so.

You could just email it as an attachment if sharing is not allowed.

regards,
Philip T

Answer 2

Open My Network Places | click on entire network | Windows Microsoft Network | the domain name | then click on the computer you're trying to get or give info. Then you can either copy or paste the files in there provided the permissions are setup correctly.