Thanks for you feedback.

Could you please elaborate a bit more on what happens on your end when using
WinHTTrack 3.49-2 on Windows x86-64 and downloading large (over 4Gb)
files?Does HTTrack 3.49-2 (you use 64-bit version I presume) also keep
retransferring large files when using feature "Update existing download" even
when the large files were already completely successfully downloaded using
feature "Download web site(s)"?
I manage to download large (over 4Gb) successfully but only when I use feature
"Download web site(s)" only once. After using feature "Continue interrupted
download" or "Update existing download" the described bugs start to happen.

I'm thinking of switching to Windows 64-bit and use HTTrack 64-bit version
from there but maybe then I run more or less into same download issues again.