I have a new computer on the way and have ordered the CS4 production premium upgrade.

What is the best way to get a clean install on a new computer?

Do I need to install CS4 over the top of CS3 on the old computer and then deactivate and transfer, or can I install CS4 directly on the new computer. (I don't want to install the old CS3 version on the new computer)

If you own a full copy of CS3, having it installed on the same system as CS4 shouldn't have any negative results, and may be helpful for certain things. We have CS3 on all of our edit systems at the office, even ones with CS4. Eventually it will be unnecessary, but I would give it a few more months before that is true. In our case CS4 has no support from Cineform, Decklink, Matrox, etc. so we continue to need CS3 for most work. It may not be necessary for simpler workflows, but it shouldn't hurt to have.

You don't have to install the prior version if you'd prefer not to. I think all you need is the old serial number, but just in case it would be a good idea to have Disk 1 from CS3 handy.

I would advise to just install CS4 if that's all you need. You should just need your CS3 serial number, and that would be the cleanest way to go.

You'll save yourself a bunch of time by just installing CS4 on your new machine. Installing both of them will chew up the better part of a work day.

You'll save yourself a bunch of time by just installing CS4 on your new machine. Installing both of them will chew up the better part of a work day.

Unless of course you need to keep CS# for certain compatibilty issues.