I'd backup first .. but that said I've run upgrades from 6 to 7 several times and never seen a problem (at least, not that I can remember).
@Mike - I tried several times but could never get a satisfactory install of Notes 7 beside Notes 6 (Notes 7 is very insistent at installing over the current version) and despite registry changes etc it never quite worked.
Just go to Notes 7 .... I always get a feeling of it being an much more stable better performing client anyway.
I'd backup first .. but that said I've run upgrades from 6 to 7 several times and never seen a problem (at least, not that I can remember).
@Mike - I tried several times but could never get a satisfactory install of Notes 7 beside Notes 6 (Notes 7 is very insistent at installing over the current version) and despite registry changes etc it never quite worked.
Just go to Notes 7 .... I always get a feeling of it being an much more stable better performing client anyway.