Did you know that you can run Adobe Photoshop (CS3 / CS4 etc.) on two computers using the same serial number?
Actually, you can do this with any Adobe product. The Adobe software license states that you don’t need to buy a copy for each computer (up to two computers), if you have a desktop and a laptop for example.
If you install it on two computers but are getting a “Too many Activations” error, this probably means that you had it installed on a third computer and did not de-activate it from there previously.
This was a problem I had because I had installed it on an old computer and then when I got my new computer and wiped my old computer clean, I had not thought about first de-activating Photoshop.
So, as I learned today, if you have this issue, just contact Adobe and they will get it working for you over the phone or online by resetting things on their servers. I was pleasantly surprised that there was not a very long hold time on the phone and the first person I spoke to was able to help me in about 5 minutes total even though I could barely understand his English (I believe he was in India).