I have lately upgraded from Vista to Windows 7, I have written about this experience in this post.
Now I because I have upgraded my original Windows 7 Professional over the RC release, things were not very promising for me. Windows 7 was not acting as it is supposed to be and Microsoft clearly had a reason for not allowing upgrade from RC. So I decided to reinstall. I was worried for 2 reasons:
1) I have already used and activated my original Windows 7 Professional key.
2) I have to upgrade from Windows Vista since the version I bought was the upgrade version of Windows 7.
In any case, I had no choice and I went ahead with the reinstall.
Step 1 - Installing Windows Vista first:
1) I completely formatted my C drive where Windows used to be installed on. Of course I made sure I backup all of my data first
2) Then I installed my Windows Vista 64-bit Home Premium. As soon as I completed the installation, I disabled the network so that it wont unnecessarily run Windows update
3) I used my original Vista key throughout the installation but made sure I didn't activate Windows Vista when asked to, again because I felt it was not necessary
Step 2 - Installing Windows 7:
1) Without doing any further tasks I popped in my Windows 7 64-bit Professional Upgrade DVD and started the upgrade process
2) I tried the option to upgrade over existing Vista but this gave me an error that I cannot upgrade from Vista Home to Windows 7 Professional. Anyway that was good, because I can actually just install a clean Windows 7 Professional from scratch, so its not really an upgrade anymore. The only catch is that Mr Gates wants to make sure I already have Vista and that's why he was very generous to sell me Windows 7 for US$100
3) The installation went smoothly. And when it started to ask me for my user name and my computer name, I made sure to use the exact ones I had used when I installed Windows the first time after activating it.
4) Then towards the end it asked me for the key. I just skipped the whole step.
5) Once the installation was fully over, I went into "Windows Activation" (right click "My Computer" and then choose "Properties"), and inserted my key and activated.
6) It was activated correctly, no problems at all. I was worried it would fail and I have to start contacting Microsoft, but luckily I was spared the trouble.
7) The existing Windows Vista installation was copied over into a directory called "Windows.old". As I had absolutely no use for that folder or my old Vista installation for that matter (remember it was just to tell Windows 7 I own Vista!!), I completely removed this folder and claimed back the precious space. There is a method to remove this folder according to Microsoft (Link:
http://support.microsoft.com/kb/933212). I just prefer the simple way!
Step 3 - Creating a system image (optional step):
1) I decided to use the backup option in Windows 7 to create a system image of the clean initial install. Later on if I need to reinstall for any reason I don't have to install Vista again
2) Go into Control Panel and choose "Backup and Restore" or if you are in the category view choose "Back up your computer" under "System and Security"
3) In the left side panel choose "Create a system image"
4) Then choose where you want to save this backup. You can choose a network location, a DVD (it might use more than one DVD depending on the size of the image), or a location on the local hard drive
4) From there on its a straightforward procedure, you just need to wait for it to complete the backup. I believe your computer wont be usable while doing the backup, so just wait for a few minutes until its complete.
I made sure I took a backup as soon as I finished installing Windows 7 to make it as clean a backup as possible. Then on the next day I made another system image backup after installing my most used utilities and all the latest updates to Windows 7.