I bought this at the beginning of the year and the early version of the software worked but you had to remember to run it each time your computer rebooted. Also in order to keep a full history of energy usage you had to keep your computer running which was a bit ironic since you probably bought this device to save energy costs! If you don't keep it running then the historical analysis is meaningless. For a while that was OK, I ran it 24x7, and it produced nice reports but I found that the longer I ran the monitoring software the slower my computer became.
A subsequent version of the software in July 2010 claimed to fix the slowness and make the monitoring software run automatically when your computer restarted but that version of the software did not work for me on Windows 7. It failed to find the transmitter. I have tried it on 2 machines both with clean installs of Win7.
Due to lack of support on this device it's now just a paperweight.