NOTE: My comments below are not as a DNN4Less employee but as a DotNetNuke Community member.
Andrew Hyde
100% Uptime is just not possible in the shared web hosting for a cheap price. If you do want good uptime, you might want to put a bit more money.
I would go as far as to say that anyone offering 100% uptime or with servers that show it are most likely not keeping all their software up-to-date since, in some instances, reboots are absolutely essential.
Everything you can imagine about web hosting needs maintenance of some kind at one stage or other and providers who are the best at managing this requirement with minimal downtime are the ones to go with.
100% network uptime is a different matter entirely and is achievable.
Here's another scenario to make you think. Well managed, a server may very will have 99.9% uptime yet your site will still not load so, for all intents and purposes, is actually down. It only takes one miscreant on a shared server of 70 plus DotNetNuke Websites (I have heard of up to an incredible 200 sites per server any one of whom could bring all the others down) sites to bring them all to a standpoint.
If you have the money and justification, even a VPS or Dedicated server, well managed, will never give you 100% uptime 100% of the time. Multiple servers offering maximum redundancy is common. However, even in that scenario, 100% uptime is a rare phenomenon.
My advice (as a DNN community member) is to seek a service provider who is honest, experienced and responsible with a demonstrable track record in maintaining servers for the highest uptime possible, whether shared or otherwise.
This is no easy task since the biggest are not always the best.
Very best wishes.