When is the right time to transfer data from old HDD to new HDD?

Data centers typically swap out storage media every 3-5 years

Ok. (HDD=Hard Drive) I think this is what you are trying to do.

When you transfer data *for example your old HDD to your new HDD. Any thing on the New HDD will be overwritten with the data from the old HDD.* You could use a usb drive as a storage device.(Up to 16GBs). So when you are ready to Transfer Data from your
old HDD to your new HDD. Before you do any of that make sure that you move ANYTHING you want that's already on the new HDD (Gamerprofiles, Gamesaves,ECT.) Onto the Usb drive and then unplug the usb for safe measures. Then transfer the Data from the old HDD
to the new one. Once that is done you can copy/move data from the usb drive to the new HDD. The only problem i can think of that can/will come out of this is multiple copy's of the same exact data, This might cause corruption issues. In my opinion, Wait till
the transfer cable because one wrong move with what i told you. You lose all data or some of it.

Hope this helps in some way

-Sage

while everyone is on the subject of transferring data, i have a question. i have an older Xbox 360 with the snap in hard drive, is it possible if i buy a new console with the hdd built in if i can transfer the data from the old hdd to the new hdd? and if
so, how would i go about doing this? thanks in advance.

[quote user="Zombie1982"] I've got an old 120GB HDD, I'm assuming that I'm going to have to pick up an Xbox Slim which I hear aren't compatablie with the old HDD's.[/quote]

No. They are not compatible.

[quote user="Zombie1982"] I do have an old transfer cable that transfered data from a 20GB HDD to this 120GB HDD, can I use it on the new ones.[/quote]

The older transfer cable will work fine.

You didn't keep your old HDD and use a transfer cable to copy all your old data to your new HDD? It's what I did.