I am trying to install the 64-bit version of the Windows 7 beta, but have been hitting my head against the same problem over and over and over again.
I tried asking about this at Anandtech, and got almost no help.
The first time I tried to install, I got a "not enough space" error, because I underestimated how much room it needed. No problem, I went back and re-partitioned to give it more room, still no go.
After several tries, I just gave it a nice 60GB chunk to chew on, and STILL it says not enough space.
Here is a pic of how Partition Magic sees my drives. Ignore the tiny drives, those are leftovers from previous partitioning that I never got around to cleaning up. You can see the K drive is the one I'm trying to install onto.
Then I thought maybe it has some kind of issue with installing on a SATA drive, so I tried moving stuff aroudn to stuff it onto the IDE HD I have, and still... same issue.
This is starting to drive me crazy, I'd like to mess with it some before it launches, just to get a feel for it, but even with all the good press it's getting I'm starting to think Microsoft has no idea how to code an installer.