Version of LW will not protect you from viruses. I do not recall any such warning about viruses. A warning you will receive about possible viruses is if you attempt to launch a program within your LW library.
However, LW 5.2 has introduced a concept of known file hashes of the most common virus files on the network, which will be deleted at moment of downloading completion.
As stated here
http://www.gnutellaforums.com/downlo...downloads.html LW 4.16 users have access to a much wider audience than either LW 5 or 4.18. LW are in the habit of stopping the earlier versions connecting to the later versions for downloading. This is an attempt to force everyone to update their LW earlier versions.
I use LW 4.16 & have access to LW 5 users & users with versions as early as 4.8 at least (which was released 4 years ago) for both downloading from & uploading to.
If using LW 5 you would not have access to the same earlier versions for sharing with. LW 5 is limited to sharing with LW 4.14 (released 2 years ago) as the earliest version.
The update messages & also possibly the upgrade messages annoy many people. Unfortunately no way of turning such messages off because they are hard coded into the program .... LW calls back home & does version checks.