1. Click the Start button, and then click Control Panel.
2. Click System and Maintenance.
3. Click Windows Anytime Upgrade.

The Windows Anytime Upgrade window appears. You can view your current edition of Windows in the upper-right corner. Click the Upgrade link, click Begin upgrade process, and then follow the prompts that appear. If you have your Vista setup DVD, you can upgrade immediately (every Vista setup DVD contains every edition of Vista). Otherwise, you’ll need to order a DVD and wait for that to appear.

If you are running Home Premium or Ultimate and you still can’t play a DVD, you probably have some DVD playback software installed that’s not compatible with Windows Vista (like, say, an older version of PowerDVD, WinDVD, VLC Media Player, etc). Try upgrading whichever you’re using to a Vista-compatible version. As an alternative to upgrading to Vista, you could also install one of these tools to watch DVDs–just google the names.

I’ve installed Vista without the key. Now, after finding the key, I’d like to install it. How is this done?

Answer:

Follow these steps:

1. Click Start, right-click Computer, and then click Properties.

2. The System window appears. Scroll down to the Windows Activation section, and click the link to enter your product key. The link might take a few seconds to appear, so be patient.

Scary message, eh? Don’t worry, it doesn’t mean you’re a bad person. It happened to me, and I’m about the nicest guy I know, and my Windows Vista license is most definitely genuine (and provided by Microsoft via MSDN).

This message about Windows being genuine is part of the Windows Genuine Validation. That’s separate from the Product Key you put in. Windows can be activated successfully, and still not be considered “genuine”. Follow these steps to Activate Windows.
Microsoft requires that you go through Windows Genuine Validation in order to download some updates and other important files from Microsoft. It’s a pain, but it’s something you should go through. To validate your software, follow these steps:

1. Visit the Genuine Validation Required page using Internet Explorer (not Firefox!), or click the Go online and resolve now link in the validation message. Click Continue.

2. On the Running The Windows Genuine Advantage Validation Tool page, click the information bar that appears at the top of the page, and then click Install ActiveX Control. If you don’t see the information bar, it means the component is probably already installed-just wait a minute for it to check your installation of Windows.

3. Provide administrative credentials when prompted.

4. Click Install when the Internet Explorer Add-On Installer prompts you.

5. After a minute or so, the Validation Complete or Validation Incomplete page will load. Hopefully, you successfully validated. If not, try activating your software first, and then returning to this process.

For help getting validated, visit Microsoft Genuine Advantage Support. If you can’t get validated, you can still use Windows–you just can’t get all the updates and toys from Microsoft.

If you skipped entering the product key when setting up Windows, or you chose not to immediately activate, Windows will eventually make you activate by showing the dialog above. Go ahead and click Activate Windows online now–even if there’s a problem, you’re not going to get into trouble.

If it doesn’t appear automatically, you can manually activate Windows by following these steps:

1. Click Start, and then click Control Panel.

2. Click System and Maintenance.

3. Click System.

4. Under Windows Activation, click the link to enter your product key (it might take a few seconds to appear).

If you didn’t enter a Product Key during setup, the Windows Activation wizard will prompt you to enter one now. Now’s the time; if you don’t enter it, you won’t be able to do much with Windows. If you did enter a product key during setup and you’re still prompted to enter one, click the Show me the details for the error that requires this change link. It’ll explain that your key is invalid or has been activated on a different computer–you can only activate most product keys on one computer.
If you don’t have a product key, or if you entered a product key for a different edition of Windows Vista, click Buy a new product key online. Then, click the Windows link in the upper-left corner, and pick your edition of Windows. Of course, you don’t have to order Windows this way; you can go to a store, or order one through an online retailer. Just be sure to get the same edition of Windows that you picked during installation (ie., if you chose Ultimate, you need to buy Windows Vista Ultimate or be forced to re-install Windows)
If you already have a product key, type it, and click Next. You’ll see an error message if there was a problem with your product key. If activation goes well, you won’t see anything–you’ll just be taken back to your desktop. You can follow the steps I showed earlier and check under Windows Activation to verify that you activated successfully.

(more after the jump)

Then, click No to confirm. Next, you’ll be prompted to pick your edition of Vista (which is normally automatically determined by your product key):

Be sure to pick the edition that corresponds to your product key. If you pick the wrong edition, you’ll either have to re-install Vista with the correct product key, or you’ll need to buy a product key for the edition you chose. You’ll have 14 days to type a product key after installing Vista.

Note: the editions that end with N (Windows Vista HOMEBASICN and Windows Vista BUSINESSN) don’t have  Windows Media Player to comply with European regulations. Those editions aren’t sold in the US.