Intel Centrino Ultimate-N 6300 - very poor connection speed

I am stumped with regards on how to fix this one.

I am running a custom built Sager NP-5135, Windows 7 64bit system.

I am actually multi booting this system (Running Linux on one partition, and Windows 7 on 2 other partitions).

The Windows 7 partitions are, for all intensive purposes, the same (configuration wise).

Here is the strange part, the wireless connection on one of the windows installations (Call it Win7_OS_#2) is perfect - great connection speed, range is great, etc, etc (So the 6300 hardware is NOT faulty).

The other Windows 7 partition (Call it Win7_OS_#1) has a terrible time connecting -- the speed is slow (read it as "unusable"). It wasn't always like this, and I don't recall when it became this way as I normally connect using a wired connection.

On Win7_OS_#1 I have uninstalled the driver, reinstalled the latest driver, scanned for virus', trogans, malware, found nothing, and I still can not get it to work properly.

I have checked all the property and advanced settings for the Intel Centrino Ultimate-N 6300 card -- they are set exactly the same as on the Windows 7 installation that is working perfectly.

Does anyone have an idea as to what else I could check to try and resolve the issue (without having to reinstall windows 7 again)?

Thanks for your assistance.

Sorry to have to bump this thread, but does anyone have any ideas regarding this issue?

bump similar issue

Ultimately I did a clean install, but before I did that I believe that I found the solution. Under Control Panel>Network and Internet>Network Connections there was another entry. I can't remember what it was named exactly as I deleted it some time ago, but it was something like "Microsoft Virtual WiFi Miniport Adapter"

If I understand how it works, it is supposed to allow you to connect another device to the Machine in order to share an internet connection. Without it I guess it won't work. It shows up as another Network adapter in the Device Manager. I had disabled it in the past and it seemed to help, but it appears that it could still cause problems. I.E. ===> cause delays in connecting to Wifi Networks.

I found what appears to be a better solution here: Uninstall Microsoft Virtual WiFi Miniport Adapter Permanantly

Essentially start up the command Prompt as an administrator and type these commands:

First Command Type: netsh wlan stop hostednetwork

This will "Disable" the device the same way as if you went into the Device Manager and Disabled it. So if it doesn't work it probably means it has already been done.

2nd Command Type: netsh wlan set hostednetwork mode=disallow

This will prevent the service from STARTING TO BEGIN WITH.
If you ever want it restarted you replace "disallow" with "allow" and it should restart for you when you reboot the machine.

Other Related command can be found here: About the Wireless Hosted Network (Windows) Hopefully this is helpful.