Sounds like malware.

Do a thorough check for malware, following all of the steps at one of these
Web pages.
Help with malware:
All MS-MVP Sites.
Consider this: Whenever a new error condition appears on your computer, it
is almost certain that there was some change to the computer soon before the
problem began.
[url]http://aumha.org/a/parasite.htm[/url]
Unexplained computer behavior may be caused by deceptive software.
[url]http://support.microsoft.com/kb/827315[/url]
[url]http://aumha.org/a/quickfix.htm[/url]
[url]http://www.elephantboycomputers.com/page2.html#Removing_Malware[/url]
[url]http://mvps.org/winhelp2002/unwanted.htm[/url]
[url]http://inetexplorer.mvps.org/darnit.html[/url]
[url]http://www.mvps.org/sramesh2k/Malware_Defence.htm[/url]
[url]http://aumha.org/a/parasite.php[/url]

So How Did I Get Infected Anyway?
For quite a few people it's by installing programs like Messenger Plus,
whose ads for malware don't identify the malware as such and try to convince
you that you owe it to the author. See also:
[url]http://www.wilderssecurity.com/showthread.php?t=27971[/url]
Don't ever do a "default" install of anything. Always choose Custom and see
what else is
being carried along. Don't install any extras you're not sure of.


-------
*Report back, please*


"Jim Kay" <joschka@newsgroup.nospam> wrote in message
news:1DE4A8B2-3146-4117-B204-8C8768F86843@microsoft.com...[color=blue]
>
> Every so often, when I start Windows Photo Gallery (on my Vista system), I
> get a prompt telling me there is an new download available that will allow
> me to read additional file types.
>
> If I click on OK, I am taken to a web page telling me that the new file
> time is a Adobe Digital Negative and the update is available from Adobe.
>
> If I click on 'Adobe' I am taken to an Adobe web page telling me 'the
> codec is not yet available'
>
> I go through this every so often because there seems to be no way to know
> for sure that it's the same error over and over. I suppose one of these
> times there will be an update I want.
>
> This has been going on for months now.
>
> Jim Kay[/color]