Attention Windows 7 users: If you haven't yet installed service pack 1 (SP1) for Windows 7, you should do so as soon as you can. Without SP1 installed, Microsoft's support for your operating system ends Tuesday, April 9th, 2013.
This isn't unexpected or otherwise shocking news. Microsoft has always supported the previous (or in this case, lack of) service pack for 24 months after the current service pack was released. Windows 7 SP1 was released back in February, 2011.
"Support ending" for Windows 7 (no service pack) means that those important security related updates released on Patch Tuesday won't be made available for your version of Windows. The solution to this problem is really easy: update Windows 7 to SP1.
Windows service packs are always free and can be installed via Windows Update or manually via a download from Microsoft.
You can read more about this directly from Microsoft, including more about the Windows product lifecycle in general:
Unless you are some large corporation that needs to vet this service pack you are being, well, silly not to update. If you are paranoid (and why not be?), make sure of a restore point. M$ can be silly/stupid but updates and service packs should be deployed immediately. Seems to be one thing that M$ does do right…