I'm running a fresh install os win 7 ult. How do i get up to 60? Ihave 20 onboard ports!
Using USB Hubs. I attach one USB 2.0 hub to the computer and then string the USB 3.0 hubs off of that. I like the Gearmo 10 port hub.
http://www.amazon.com/gp/product/B00BZABGWK/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1So your motherboard really has 20 ports? What kind of computer/motherboard is that? Is it USB 2.0 or USB 3.0 ports. Block Erupters require stable .5 amps each to work correctly and the original first run which I believe were the saphires drew a little over .5 Amps. You don't usually get that for all ports with USB 2.0, but with USB 3.0 .9 Amp per port is part of the spec so those hubs usually have hefty power supplies. So I would say that your Mother Board isn't really supplying 10+ Amps to the 20 USB ports.
After following os2sam's advice about external powered hubs, if you still have issues look at
https://bitcointalk.org/index.php?topic=300638.0 for advice how to 'clean' your device manager from old unwanted USB settings.
You need to configure your USB hubs in a way that doesn't span too many levels, or Windows will complain.
I used to run 40 BE's on both windows and RPi, sadly now they consume more electricity than generating BTC.
Cheers