I have been informed by iYogi (Dell "support" in India) that the "microsoft security layer" has expired on my Windows Vista Home Premium which was installed in Jan 2008 when I bought my Inspiron 1420 from Dell. Is this possible ? I have automatic Windows Updates turned on. iYogi wants me to renew this for a fee. Does the microsoft security layer need to be renewed ? I have never re-installed the Vista operating system on my laptop.
This sounds like a scam to either a) get money out of you or b) gain control over your computer.
Don't respond to them any further.
You can use the links on that page to ensure that your version is up to date.
Whilst ChrisF is pretty much spot on, and I believe that the person is trying to scam you for money, but there are a few times where MS Security Essentials can be out of date.
If you have one of the early versions, there were a few manual updates every so often that updated the scan engine. These were not automatic and required you to do something.
If however you did originally see the green icon / it showed everything was correct, then, you had the latest version as if it requires manual intervention, it will be orange and let you know what steps are involved.