14 of 15 people found the following review helpful
Trouble getting TL-WN821N to run, Zone Alarm Free was the problem,
This review is from: TP-Link TL-WN821N 300Mbps Wireless N USB Adapter (Personal Computers)
Using a Windows7 Pro 64 bit PC. I had trouble getting this adapter (mine is v4.2) to run. Windows reported that the device was working OK but there wasn't any networks shown as available to connect to. I spent many fruitless hours trying various suggestions and advice from the internet to no avail. No one mentioned Zone Alarm (free)! Pity as that was the problem.
I uninstalled ZA (free)and I finally was allowed to click on "Manage wireless networks" in Network and sharing centre/Control panel and added the password etc. The problem then went away.
The adapter works very well. The correct driver for v4 with Win7 64 bit is, DriverVer = 03/25/2011,1013.0.0325.2011
I re-installed ZA (free) afterwards and they now work happily together. I hope this info helps someone with the same problem.