Home Premium to Ultimate?

I bought Ultimate more than a year ago and found I couldn't use it on my old computer. So it sat unopened and I have still have it.

New computer has Vista Home Premium. I have been up a week. Am finally able to somewhat function. Feel like I am driving a car in London on the wrong side of the road.

Should I install Vista Ultimate now replacing Vista Home Premium? Or get the upgrade from Home to Ultimate from M$? Or just stay with what I have?

I downloaded SP1 before I started all this. I really don't want any more downtime.

THanks.

" I really don't want any more downtime."

So don't bother installing Ultimate unless there are specific features in it which you actually want and which are not in Home Premium.

The only practical advantage in Ultimate I'm aware of is that you can connect to a domain. Home premium can still connect to a simpler kind of network though.

Vista Ultimate's "complete system backup" which is Microsoft's attempt at saving backup disk images is not as good as proper imaging programs such as the free Seagate DiskWizard or Acronis TI.

If you do want to use Ultimate, there's no need to buy the upgrade as you already own an unused copy of Ultimate.

I think it's better to do a fresh install of the higher edition, instead of doing an in place upgrade to an existing install of Windows, which can sometimes go wrong.