Have 10pk license of KAV workstation version
english 6.0.2.678 I happend log onto KAV and noticed that the current release is 6.0.2.690 Is there any way to have automatic engine/version updates/upgrades occur verus me manually noticiing that I'm no longer current and manually upgrading?

Sorry version (or build upgrades) need to be redeployed via a new AdminKit package.

can I install the new version over the older one or must I first un-install the old version?

is the NDIS problem fixed in 6.0.2.690?
can't find any information about it in the release notes.
I've heard that the problem was fixed in .686, which was not an official release...

You can redeploy on top yes.