my windows viata ultimate x64 is not act....

I just looked this up you can visit there website or you can even activate it by phone I looked at a set of instructions here they are

How do I activate Windows?

You can activate either online or by phone. To activate online you need an Internet connection. Activating by phone requires interacting with an automated phone system.

To activate Windows on this computer, do the following:

Open Windows Activation by clicking the Start button

clicking Computer,

clicking Properties,

and then clicking Click here to activate Windows now.!

If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
You can then select the method you want to use to activate.
Note If you chose to automatically activate Windows online when you set up your computer, automatic activation begins trying to activate your copy of Windows three days after you log on for the first time.

This is what I copied from the website which is

Windows Vista Activation

hope this will help you

Sometimes you might have to wait for it to prompt you. Like some software does for example when I installed a new graphics card it wouldn't work to its ability 5 days later it said it would now finish installing software for the card it might be the same for the activation don't wait over 30 days for it though otherwise you lose some functionality of the OS