I am not able to access any of the information in the chm for the 2010 ctp.
Move the .chm to the root of your drive (e.g. C:\) and open it from there, you've probably got it in a long/incompatible folder.
Ooops, I feel a bit daft. I am running Windows 7. The fix: right click the .chm and click unblock in the properties dialog.