I'm sorry, I am able to select past day, and past week in the free version. If I select past month, I get the notice that it is limited to 7 days history.
When I click the report button, I hadn't realized, it was defaulting to today's date, ONE YEAR AGO (woops). Which is why I was seeing the error.
The other question, regarding the resolution. What I would like to be able to do is is look at particular events on certain servers, and see what CPU/Memory/Disk impact they had. So for example, I might need to look at the cpu usage for a 15 minute period last friday for just one VM. 5 minute increments aren't very useful in that case.
I understand keeping records for every 20 second interval, for all objects for all time would probably not be feasible. I'd like to be able to enable "detail" level resolution for certain counters/objects, and maybe select a different retention period for that detail.