You should always deactivate it. Why? Well, maybe later in time you'll wanna use CS4 again. Maybe you get a laptop or something rather. If you deactivate CS4 now, then you won't have any issues if you want to use it again for whatever reason.
but if i don't deactivate cs4 version i have problem with cs5?
It's not necessary to deactivate CS4 in order to install CS5
thanks to all
Installing an upgrade USUALLY only requires you to have the previous serial number... you should not even have to have CS4 installed
my doubt was if I have to deactivate cs4 (which is in one hard disk) before to install cs5 version (that is an upgrade) and it will be installed in another hard disk
That is actually a good question, because I have not heard adobe address that particlar issue. I'm pretty sure the licensing agreement does not allow you to keep the version you upgraded from active on another computer at the same time you are using the new version. But I don't recall it coming up. Adobe is clearly okay with keeping multiple versions on the same machine, since install instructions address this.
In any event, there is no problem activating the new version with the old version(s) still activated. I am only using CS3 and CS4 (which are on an XP machine) for testing to answer questions here on the forum. CS5 is humming along on its own machine. All are activated. But I'm only using one at a time.
I'm going through this CS4 -> CS5 upgrade right now and this aspect crossed my mind earlier today.
I was tending towards what you think the licensing agreement says but then a little voice said: "You paid hundreds of dollars for the first product. Then hundreds more again for an upgrade. Then hundreds more again for another upgrade. If you add up all the $$ then wouldn't it be a real cheap (and nasty) trick for the manufacturer to say you can only legally use the latest product? Didn't you pay for the previous product already? Does that payment somehow go away?"
From other posts I get the impression that having your previous products installed on the same or another machine is ok. The agreement should only talk about the product it applies to (but I have not trolled through it to investigate).
In fact I think you could deactivate, uninstall, reinstall and reactivated later on another platform without a problem. if it all goes right that is.
Ah well ... there's only one of me even if I have many machines.
My two cents ...
Absolutely you can do a clean install of CS5 Upgrade using only the SN from the old CS4, and you certainly still own CS4 and can install it on another computer. This is the point of "deactivating" CS4 prior to removing it from what's to be the CS5 system. That way you will retain your 2 CS4 activations for install anywhere you like.
You did purchase CS4 and are entitled to its continued use regardless of any subsequent software upgrades.
It's clear to me that the high price of admission for the first purchase of your original full version is simply the ticket for admission to the "club".
Once paid, the real price for the product going forward is simply the upgrade price. You could have a shop with 2 activations of each version on a roomfull of computers- and why not, you paid for them.
I currently have CS5 on this system, CS4 on a laptop, and CS3 on another older system.