Homegroup File Transfer Slow, up to just 1mb/s

[nfsworldrace]

Hello im pretty frustrated about my situation here, i created a homegroup and even map network drives on each other but when i try to transfer files it's just very slow its capped at 1mb/s and sometimes drops to 0.3mb/s

my pc1 is connected in the wireless router through ethernet cable while,
my pc2 is connected through wireless n adapter
also modem is connected in the router through cable

 

[Kewlx25]

What OS version? vista, Win7, etc?