I got this notice in my mail but I don't understand exactly what it is for and if I should download it or not.
It is from Trend Micro and it says:

As of March 11, 2005, TrendLabs has released Official Pattern file 2.488.00.

If you are running a Trend Micro antivirus product, it should automatically update to this latest pattern file. You may also manually download this new pattern file from http://www.trendmicro.com/download/pattern.asp.

Important Note:
Users of non-NPF (i.e., old 3-digit pattern format) compliant products will not be able to update to the pattern release indicated in this email. Non-NPF compliant products can only update to pattern 991, which was released March 7, 2005. TrendLabs urges all affected customers to apply the New Pattern Format solution at http://www.trendmicro.com/en/support/npf/overview.htm or upgrade to the latest product version to address this limitation.

I don't know what I am suppose to do so I am hoping someone
can explain this to me and let me know if I should download the programs.
Thanks
PF

PF - It doesn't look as if anyone is using the same antivirus program as yourself to be able to advise. I think if I was, I'd go ahead and update anything recommended. Perhaps just hit the program's 'Update' button to start with and see what happens. Have a careful read of the page your 2nd link leads to. Follow the link on that page that says 'click on this link' (2nd paragraph) and also have a good read of that. There is an Affected products page where you can tick the program you are using to check if it needs updating. Just follow whatever advice is given.

Just in case you are wondering. The links sent by e-mail (always worth being a bit wary of them) and that have subsequently been posted here, lead to the genuine Trend Micro site according to SpoofStick.

Most software manufacturers update their product once in a while. Sometimes that involves parting with some cash, sometimes not.

Thank you for the help TW. It all sounded Greek to me.I shall read it all and follow it's instructions.
PF