SOLVED: WiFi dropouts under Windows 7 on Retina Macbook Pro

Question

I never found the solution to the problem but I found hints around the web. After hours of playing with router settings and driver settings, this problem is solved. Wanted to log down because I did many searches and did not find any clear guidelines. (I can find them when searching for what I now know is the answer)
Short answer: Disable 40MHz in the router. Use only 20MHz. (Not auto, not both).
Situation: I have to use Windows 7 as it's a work computer (for various reasons). At my home network (only - other places OK), I could never connect reliably to the wifi. Sometimes it would appear 'fast' (I live in China so nothing's every blistering) and sometimes I'd just get the yellow hat on my wifi bars indicating no connection.
I knew it was a problem with my computer/drivers because
Other hardware in the house (ipads, other windows computers, phones) all connected as one would expect to the internet.
My computer couldn't even get a good connection to the router (the config page). I.e. it was a LAN issue.
Manually setting some parts of the internet settings (e.g. IP address, DHCP server) did not help
What I tried
Cleaned out all the junk in the computer (there was an old Java vulnerability but not sure if that had any impact)
Removed some junk software
Stopped many services systematically (thinking they were blocking the connection before even my netstat software) - I was suspicious of some installed by my bank (remember where I live)
Changing some wireless adapter settings. E.g. changed in AP mode 'higher performance' to 'broader compatibility'.
Upgraded router firmware, using a fairly normal ASUS RT-12N, but very old firmware
Final solution: I had read somewhere something about Apple wifi hardware and bluetooth interfereing. even though I have no bluetooth hardware, I thought it might be a cause. So I set the router to 20MHz only rather than 40 and 20 simultaneously.
Results:
Stable connection (1 day uptime so far)
Much higher bandwidth (about double previously... i.e. 500-800KB/s, which is fast for where I live)
Lower latency (quicker loads of some previously slow pages
Obviously I have only tested this on one computer. Hope this works for you.

Answer 1

Go through and read these articles they walk you through quite thoroughly
Mac 101: Using Windows on your Mac via Boot Camp
https://support.apple.com/kb/HT1461
Boot Camp 4.0, OS X Lion: Frequently asked question
http://support.apple.com/kb/HT4818
http://manuals.info.apple.com/en_US/boot_camp_install-setup_10.7.pdf
http://manuals.info.apple.com/en/Boot_Camp_Install-Setup_10.6.pdf
create a Windows support software (drivers) CD or USB storage media
http://support.apple.com/kb/HT4407
The Boot Camp Assistant can burn Boot Camp software (drivers) to a DVD or copy it to a USB storage device, such as a flash drive or hard drive. These are the only media you can use to install Boot Camp software.
https://support.apple.com/kb/HT4569
Installation Guide  Instructions for all features and settings.
Boot Camp 4.0 FAQ  Get answers to commonly asked Boot Camp questions.
Windows 7 FAQ  Answers to commonly asked Windows 7 questions.
http://www.apple.com/support/bootcamp/
When you drag the slider on the partition side, that was all you needed - it should be 40-60GB at least.
The disc I assume was physical retail etc and because you don't have an internal DVD you had to put USB-DVD support software on a USB flash drive.
You downloaded the Windows Support Software package as well, which needs to be run and installed on USB FAT as well.