In response to post #10474770. #10474825, #10475172 are all replies on the same post.
Shouldn't be anything wrong, other than Window's usual B.S. about executable files that don't originate from big publishers who register their products with Microsoft. Also, it sound's to me like it's on your browser that the 'blocking' is occurring which could mean that you are A) using Microsoft's Internet Explorer, in which case there should be an override for that block in the same warning message (but really why you aren't using an open source browser like Firefox, Chromium or Vidalia is beyond me). Or B) you have some over enthusiastic Anti-virus browser plug-in that in similar fashion to MS IE doesn't like it when people choose to use open source software (NMM is open source - and can be downloaded directly from SorceForge). You should be able to override the Anti-virus plugin either on this particular case by looking at the blocking history or by simply temporarily disabling it's plugin while you download the item.