Windows 7: Win7 Download speed slow when no fullscreen windows

When i dont have fullscreen programs or windows my download speed goes down, 75kb/s, when i open anything fullscreen, Windows media player, firefox, my download speed goes normal 1000kb/s.
I put powersaving mode best performance but it doesnt help.



I have 10/1M internet. WIndows 7 ultimate , TP-link TL-WN881ND Pci express adapter(wireless)
This happened when i changed vista and Realtek 8185 wireless adapter to Windows 7 and TP-link.
Utorrent in my laptop downloads normally.
I have kaspersky internet security 2013 and i have tried without it and without windows firewall.
Something is wrong in my windows but i have tried to switch off powersaving and everything



Edit: WHen i turn windows aero off, networks goes normal. Wtf?