Well there is the convenient method:
Uninstall Vista, Install XP
There is the clever method:
Uninstall Vista, Install XP
And there is the method, that in long term will save your nerves from destruction:
Uninstall Vista, Install XP.
HDD Formatting. It save my life.
Okay, to cut the jokes, unfortunately it seems that many functions of Nexus or it's mods will not work under vista. Including (i think) the DaTool made by ElFarto, or something else in the course of installing the New Conflicts mod.