for one thing check with your college.. apparetly some colleges blocks the port steam needs to use
and another thing it really depends on how fast your connection is
it wouldnt matter.... putting the key into steam will make steam ask for the cd or dvd...
since there is a different key given for cds... Steam will recognize the code to be a code given on retail copies hence it will ask for the retail copy to install the game
Thing is im sure valve would of made it possible for no cd to be needed but. the sad thing is it is a REQUIRMENT made by the companies that distribute the game for sale in retail stores..
If no cdprotection is used the distributors ie, vivendi will not release it..
wait a while in most cases...
its possible you could install on more thasn one but they cant be active at the same time...
play hl2 on computer 1 you cant on computer 2
play hl2 on computer 2 you cant on computer 1
i wonder if you make a cd backup of the files maybe it will work allowing you to use a cd....
as steam also gives us retail users the option of backup files