i think there is few steps but it would not be any difference

1. Update Origin (download latest origin version for BF3)
2. Insert DVD -> Click Install (it will ask for cd key etc all self explanatory)
3. Wait for 1/2 hour @ 6.5MB/s
4. Upon completion; make sure your internet is still on as it will check for patch... download the 500MB patch (if you were disconnected at this time, do step 2 again.. I had 1 hour chat with EA looking for the patch link)
5. start the game as usual

there is no link; hence the 1 hr chat...

same solution; resintall the game to get the link

aiyoo..thats y I told u guys to install UPDATED origin before putting the DVD disc; u get many prob later on...

first ask for guide; then when put up; not reading it..sigh