I wanted to upgrade windows xp from its old version that is SP2 to SP3 and I would like to know, is it even possible to upgrade
or I have to buy another CD to install it  again.
Hey Joey Fergus!
If you want to install windows Xp Service Pack 3 on Service Pack 2 then do not worry about this. There are two possible solutions you have.
Solution 1:
First solution is that, you can download a service package of service pack 3 from the internet and install it. Your windows will be changed to service pack 2 to service pack 3.
Here is a link from where you can download the service package.
http://www.microsoft.com/en-us/download/default.aspx
Solution 2:
Second solution is the same which you have already mentioned above. You can buy a new Windows Xp Service Pack 3 from the market and can install it on your system.
Just boot from the CD or DVD and upgrade the windows.
Thanks
Hi Joey,
Another way on how to upgrade your XP SP2 to XP SP3 is via Windows Update. If you are a genuine windows user, most of the time, the recommended Windows Update is "Automatic". It will automatically download and install available updates for your Windows OS such as the updated Service Pack. You can also set your Windows Update to manually so that only recommended updates will be downloaded and installed, including the SP3.
To check available updates:
Note:
Review and accept the Microsoft Software License Terms. When SP3 is downloaded, a setup wizard will help you to install all its component.
Best Regards,
Fischarinta Cra
Thanks to all your solutions, I downloaded the SP# off of Microsoft's website and I had no trouble with installing it and upgrading to Windows XP SP3
