Finding out what Windows Vista service pack you have is important because you want to make sure you have the latest one installed.
Aside from just making sure your computer is safe from the most recent security threats and Windows bugs, keeping Vista updated to the latest service pack ensures that new software works properly and that your installation of Windows Vista is still fully supported.
Windows Vista Service Pack 2 is the most recent service pack available for this version of Windows.
Follow the steps below to determine what Windows Vista service pack you're patched to:
Click on Start and then on Control Panel.
Tip: Skip the next few steps by typing system in the search box after clicking Start. Then choose System from the list of results and then move on to Step 4.
Click on the System and Maintenance link.
Note: If you're viewing the Classic View of Control Panel, you won't see the System and Maintenance link. Instead, double-click on the System icon and proceed to Step 4.
Click on the System link.
In the Windows edition area of the View basic information about your computer window you'll find see information about your version of Windows Vista, followed by the service pack that's installed. See the screen shot on this page for an idea of what you're looking for.
Note: If you don't have a Windows Vista service pack installed then you won't see anything at all. Unfortunately, Windows Vista doesn't specifically note it when you don't have a service pack installed.
The latest Windows Vista service pack is Service Pack 2 (SP2).
If you don't have Windows Vista SP2 installed, or don't have a service pack installed at all, then you should do so as soon as you can.
Not a Windows Vista user? See What Windows Service Pack Do I Have Installed? for specific instructions for your version of Windows.