Please try the following steps:
- Verify your security settings on both ends. Intel WiFi Products — Data rate will not exceed 54 Mbps when WEP or TKIP encryption is configured
- Analyze your environment for interference and select the best channel. You may use programs like inSSIDer* 3 or WifiInfoView. Intel® Wi-Fi Products — Possible interference by other wireless devices may impact 802.11n performance
- Try disabling uAPSD in the adapter properties. Intel® Wi-Fi Products — TechNote: Access Point interoperability issue with uAPSD