I have to second Sebastian's words -
Not only did I have to migrate my sites from a windows 2000 server to a windows 2003, I had to create new folders, new naming conventions, change IP addresses for about 200 clients. It took me some time to sort out a couple of things - like - xml files that were reading wrong folders on a 2.1.2 site but if your hosting company is using virtual directory eg.. domain.com/portal - rather than domain.com (which is what I use) then maybe there is something I don't know about.
But i've also developed sites locally for clients, then delivered to them via email, portals they just attach and it's a site to go..
I think your hosting company just doesn't want to do it - but if you're only paying a couple of dollars per month - then it could be one of those hard jobs they find isn't worth their money.
I can assure you that DNN does migrate and it's been easier for me to move my DNN sites to another server than some of the older asp ones.
So, look for an other hosting company if it's too hard for them.. and just because they're listed here doesn't mean they are endorsed by DotNetNuke - they pay to advertise here.
Sorry if I seem a little .. testy .. in my attitude - I just find it frustrating at times with the misinformation out there to confuse or trick people into thinking these things. And.. I'm not an IT techie - so if I can do it surely a 'professional' hosting company should be able to.
Nina Meiers