Is the speed on your old computer 4Mb/s or 4MB/s? 1B=8b, so 500KB/s=4Mb/s.

hemgutie wrote I followed the steps to install the drivers manually and I still have the same problem. I also shut down off the antivirus and the firewall but it does not work either. In the device...

You may check this: http://www.tp-link.com/us/faq-1076.html

It's better to contact TP-Link support at support@tp-link.com

The extender supports that, maybe some compatibility issue, but there is no big influence with MPDU disabled.

it only support 32 for mac filtering rules.