Here's what I finally did to get 181 erupters online in Windows 7 64
1 - Reinstalled the operating system
2 - Installed all the drivers
3 - Installed any and all software
4 - Created a RESTORE POINT (IMPORTANT: Do not insert a single erupter before this point)
5 - staged 10 erupters in their usb slots at a time, up to 100 per bus (don't be fooled by separate ports on your computer, they may still be on the same bus). A high number of USB devices will make your USB buses quite cantankerous and you should allow 30 seconds at least between device stagings
6 - Make sure they are showing up without error under the COM ports in the Device Manager.
7 - launched a separate instance of CGMiner 3.1.1 for 10 erupters each (I find 3.1.1 is much leaner and more stable than later versions)
If for any reason I need to bounce my rig, I've found that the COM port allocations get messed up and eventually CGMiner can't find all my miners. To fix this, I actually perform a system restore to my saved restore point. This is the only way that I've been able to guarantee purging of COM port allocations and have a fresh start at step 5 above.
T'is a thing of beauty