I get this message everytime I boot up or I try to run WD. I am using vista OS. What do I need to do to correct this. I can't think of anything that was done which would coincide with this happening.

Are you sure you have the latest version of Windows Defender installed?

Try going to the Control Panel
- Add/Remove Programs

Then download and install the final released
version of Windows Defender from
http://www.microsoft.com/athome/security/s...re/default.mspx

This morning it was fine and I got the error while running a scan. I then restarted the scan and it went fine. I don't know what to think.

I read the other post that all pointed to the same solution to uninstall and install the latest release. But I can't because it is a part of the OS. Also I read an article that said the same thing but it was from the end of 2007 I think.

I use XP, but look under Services & see if the Windows Defender Service Startup is set to Automatic & that Log -On is set to Enabled. If no luck, or if the problem keeps occurring, you may have to disable it & keep it from running at start-up.

Related links:

Disable Windows Defender Service (as stated above, check first to see that it's enabled)

Disable Windows Defender

Remove Windows Defender From System Startup