Code 0x80240022" Windows Defender won't update.

Here we go again. I can't find a way around this in Vista. Any ideas?

I haven't seen this one on Vista. Here's something to try, though:

You may need to run the cmd prompt with Administrator privileges--so right
click and elevate to a command prompt. cd to:

\program files\windows defender

Then:

mpcmdrun -RemoveDefinitions -All
mpcmdrun -SignatureUpdate

See if that takes care of it.

Error Code:0x80240022 Windows defender can not update in Vista

Solution :
1. Remove the current signature file. To do this, click Start, click Run, type
Msiexec /x {A5CC2A09-E9D3-49EC-923D-03874BBD4C2C}
and then click OK.
2. Open Windows Defender. To do this, click Start, click Programs,
and then click Windows Defender.
3. Check for new definitions. To do this, click the Help options arrow next
to the Windows Defender Help icon, click About Windows Defender, and
then click Check for Updates.