Dreamweaver MX 2004 serial number invalid on Windows 7?

Question

I'm trying to switch to a new computer.  I uninstalled Dreamweaver MX 2004 (also called Dreamweaver 7) from my XP machine and tried to install it on my new Windows 7 Home Premium machine.
After I entered in the last digit of the serial number, a red x appeared next to it. The only button available was Go Back. In other words, it said my serial number was invalid.
I entered it a couple of more times and then tried an experiment. I installed it again, entered the exact same serial number, and there wasn't any problem. That is, it's definitely a valid serial number.
Then I found an update to 7.01, which I installed. Now I could enter the serial number and it accepted it, but when I clicked Next, it said that this update required the serial number of the previous product. So I tried entering the serial number for Ultradev, which I believe was the previous product. (If not, it's the only other Dreamweaver disk I have around.)  That didn't work, so I thought maybe 7.01 was looking for the serial number for 7.00, so I tried that. That didn't work.
Any suggestions?
I have only one web site that I maintain using Dreamweaver, which is why I haven't upgraded. I'd hate to have to go back to Notepad (actually, I'd use Notepad++ if I had to).
I just remembered something. When I installed it, I accepted the default directory, which was Program Files, not Program Files (x86).

Answer 1

I fixed it!
On http://www.adobe.com/support/contact/, I chose "I need help activating or deactivating my software". It says:
"If you've installed on more than two computers, you must deactivate one copy by starting that software and choosing Help > Deactivate."
Fortunately, I still have my old computer. I re-installed Dreamweaver there (I had already uninstalled it) and chose Help > Activation > Transfer License.
Transfer License became grey (unavailable), which I understood to mean it had deactivate my license.
I went back to my new machine and did this:
1. Copied the Dreamweaver 7.0 disk to my hard drive.
2. Right-clicked "Install Dreamweaver MX 2004.exe" and chose "Run as administrator."
3. Started Dreamweaver. When it asked me for my serial number, I entered it, and it accepted it! Then it asked me for the serial number of the previous version (because it was an upgrade disk). I entered the old serial number (with hyphens) and it accepted it!
So, in other words, that was the problem: I had to deactivate it on my old machine.
After getting it to accept my serial number, I closed it and then ran the 7.01 update, once again running it as administrator.
Now the only problem is that importing my .ste files doesn't work. I used Manage Sites > Import and chose the .ste file, but got an error message that says "No items match your search."  I puzzled on that one for a bit. Was it saying that it couldn't find my .ste file? I could find my .ste file, and it could, too, because it showed a list of them when I clicked Import.
I opened one with Notepad++ and discovered that it's an XML file. I think I now know the problem:  The .ste file has pathnames in it that represent the file structure on my old XP machine (D:\Documents and Settings...).  The file structure on my Windows 7 machine is C:\Users\[username]...
So, after dinner, I need to search the forums on what to do, or back up my .ste files and then try editing the paths with Notepad++.