There are some Troubleshooting steps I want you to do. Please check the following link that contains more information:
Also, can you please let me know if this card was integrated or if it came along with the system?
So what am I exactly supposed to do? I looked at your troubleshooting information and all the settings are as described there.
The card is integrated in the laptop - I haven't installed it myself.
I have an apple airport Extreme router - if this is of any help. AS I said whenever I turn off the network card and then turn it again -> it is all back to normal...
We have received reports from other customers saying that the Airport router is failing with this card. Have you tested the wireless card with another router or connection?
This may be of interest. Enabling the power management option "Allow the computer to turn off this device to save power" makes a difference on the speed in which the connection is resumed. I have a Lenovo Thinkpad W520 with Windows 7. I have previously turned off this option so that the computer did not turn off the wireless device but noticed that it was taking over a minute to reconnect once the laptop came out of sleep. When booted the first time the laptop connected within 10 seconds. For some reason when "Allow the computer to turn off this device to save power" is enabled (box checked) my network connection is once again re-established in less than 10 seconds once the laptop comes out of sleep.
I previously uninstalled ALL of my wireless device drivers and removed all my profiles to narrow down the root cause and this is what I found after going back to the original 6/16/2013 intel driver provided with windows 7.
All, sorry on correction on my post. This was associated with the slow "re-connection" speed after sleep mode NOT a slower bandwidth / network speed.