You're off topic for this forum, which is dedicated to Windows Live OneCare.
You may have mistyped the key.
If you are getting an error about the key being invalid, you are mistaking at least one character or you have a misprinted key. The latter is very rare, though it can happen.
I hate the font that they use for the key - some characters are miserable to discern. J and I look all too much alike, as do O and 0.
I recommend that you use a magnifying glass to check the characters closely - I find that I need to do this.
You can either contact Acer support for help or Microsoft - http://www.microsoft.com/genuine/ProgramInfo.aspx?displaylang=en&sGuid=1195812f-8d19-4f32-9cc2-f77e949206ec - there are resources available from that page.
-steve
Microsoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator
