Windows 7 64bit and USB WLAN adapters

Try this.

With the adapter connected, go into device manager and check what the driver is called.
Unplug the USB adapter.
In Device Manager, go VIEW -> SHOW HIDDEN DEVICES and locate the driver.
Right click it and uninstall it.

Now I'm pretty convinced that the USB is somehow screwd with the WLAN adapter(s). If I plug the adapter and go to Device Manager to look at the USB drivers, Windows hungs until I remove the adapter again...

Found following in the interwebz: ASUSTeK Computer Inc.-Forum- P7P55D Wireless Adapter Problems

I'm not the only one having these problems with that motherboard. Too bad the Asus P55 bios updater requires floppy disk drive. Something that I personally regard as ancient thing. I haven't had in my machines since... 1999 or so...

God damn this makes me so pissed...

And lets put the final solution here also...

Solution found. Problem was not the USB wlan adapter or Windows 7 but Asus P7P55D motherboard. It has some issues with USB. So download new bios from:
ASUSTeK Computer Inc.-Forum- BIOS 1207 released December 14, 2009
Unzip the file and copy .ROM file to your USB memorycard (and leave it to machine). Don't read the bios updater manual. It talks something about making boot disk. It's not required at all. Boot the machine to bios. Under the utilities there is EUpdater2 or comething like that. It can be used to update bios. Just select the .ROM file and flash it. When the computer next time boots your problems are solved.

There might be some useful information here:
WLI-U2-G300N on Windows7?! - Buffalo Tech Forums

forums.buffalotech.com/t5/Wireless/WLI-U2-G300N-on-Windows7/m-p/29232/highlight/true#M4693

I know that's for a specific wireless adapter, but the steps I went through to troubleshoot my problem should work for many people. If you can't find drivers to something, find some other hardware the has the same chipsets and see if it has a driver for your OS.

USE SYSTEM RESTORE and make a manual restore point before messing with any drivers. That way it's a lot easier to recover from a BSOD.