This is going to sound crazy, but if you haven't yet resolved this (if you have, I'd love to know), try booting up with the laptop power plugged in and fully charged and then connecting. That's the exact issue that I am having. Other posts that I've researched
have shown that this issue is related to Windows 7 (and apparently an issue with Vista, too -
http://support.microsoft.com/kb/935222) with WPA or WPA-2. In the Vista issue, they cite AES encryption as a factor; in my case, it's AES or TKIP. If, however, my
laptop is plugged in and charged, I can connect, with no issues! If, after connecting, I unplug it, it will stay connected until the charge drops below 95%, and then it disconnects.
This isn't a device issue (mine's not an Intel adapter) or a driver issue, or a WPA issue. From the posts that I've seen, these are laptops that are compatible with Windows 7 (mine's an Acer that came with Windows 7 and has this problem out of the box).
So, while writing this, I decided to poke a bit deeper into the power settings and I may have actually resolved this (Microsoft take note - maybe turn this into a KB article):
Windows 7
Go into your power options (Control Panel - Power Options)
There are 3 options: Balanced, Power Saver and (may be hidden) High Performance.
Either choose High Performance (there's no Save or Ok; it changes immediately) and try connecting again
or
choose either of the other plans and click "Change plan settings" and the "Change advance power settings". Scroll down, if necessary, to "Wireless Adapter Settings" and click on the + to view the "Power Saving Mode".
Click the + again to reveal the options for "On battery" and "Plugged in". For both, choose 'Maximum Performance'. Any of the other three options ('Low', 'Medium' and 'Maximum Power Savings') will cause this issue.
Let me know if that helps.
Microsoft may want to investigate this further; I had set my adapter such that "allow the computer to turn off this device to save power", which I would think would override any other power settings. The adapter wasn't getting powered down, but
clearly even 'low power saver' mode was somehow affecting the adapter's ability to perform a proper key exchange. It would be interesting to know if the issue found in Vista that I mention above was similarly related.
Thanks,
Tim
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