Low signal with Netgear RangeMax Mimo WPN824 and Dell Wireless 1370 WLAN

I have a DELL Latitude 120L with a Dell Wireless 1370 802.11 n WLAN netcard.

 

Recently I bought a RangeMax MiMO wireless Router (WPN824) with a ADSL connection attached to it. Another PC is directly attached with a LAN cable to the router. The internet here works superb.

Formerly it worked perfectly and the internet strenght was [good], but now the strenght is pure and the internet hardly works...???

Can any one help me.

 

Thanks