- Install avast!
- There will be a 400.vps file in your computer.
- The downloaded vps file must be just an increment of that one, already there.
Other antivirus (and antispywares) do this, reducing the size of the standalone download because you have already other virus database in your computer. In case of avast, the one you’ve installed in 1.
I don’t think it’s that much complicated to follow…
Well, just repair avast installing it again (either by running setup.exe or Add/Remove programs applet).