Product review (2 stars): Would not work with Win 7 64bit
Well built unit.  Would love it if it worked.  Win 7 64x system - the drivers and software worked.  BUT I can't get more than 768 readings - any data after that is in error.  Data download fails comnpletly if set for 2000 or more data points.  Tech service a little slow but they walked me thru several possible problems, concluded my unit was defective and shipped another.  2nd unit arrived and performed exactly the same.  More email tech support and attempts.  Tried a second PC with Win 7 64x, than a Win 7 32x PC - same performace.  Tech support concluded second unit defective and sent a third.  Same results.  Used supplied CD software and also downloaded (same version) from thier website.

I found the apparent web site for the company supplying the drivers.  Downloaded thier software development kit - it had different driver version but same result.

I now have 3 units that work well if set up for 500 datapoints (or less).  I wanted 2 to 10 sec data collection for my current project, but will settle for 10 minute data collection to get this job done.  Will need to do a little bit of 2 sec collection to make sure I am not missing some short term variation.  Lots and lots of extra work - the only good side is I ended up with 3 units (no return requested for the "defective" units).  When I get time I will build up a Windows XP on my computer to see if they will work with older Win systems.

The latest Extech software is version 5.6 as I write this - its from early 2011.  Win 7 64x driver is version 3.3.  If you see later versions available than maybe they have fixed the issues.

Did I get three bad units or does software bug exist that prevents unit from working fully on Win 7 system?  Either is bad if your system is Win 7.  I think its a Win 7 issue and will continue to correspond with tech support, but regardless of future outcome the unit has earned a two star or less for me.