A little help and advice on how one ADSL

So I explain the situation. I have a BTC modem with wireless module of these black Pirelita model DRG A124G. Too in the living room of the apartment. The bedroom is fished three features as Windows XP, however, very slow to open pages and three hundred Dawn bites your IP over DHCP. And even if I manually set it, even Gateway and DNS1 and DNS2, still the same thing. We are talking about a desktop PC test card on ASUS - WL-167g here it here. I tried with a laptop card Ateros AR5006EX, it had no problems. I tried the above map of the laptop and had no problems. I tried it on all USB ports on desktop PC and did not want change and will not work correctly. It occurred to me that Windows-a can be smeared something and reinstalled, no effect of course. I took his identity card - TP Link WN422G, so hey. Insert it into the USB port on a desktop PC and slightly improved things, but again the effect was not satisfactory. Low signal even earn Windows, that add up to 32 or 48Mbita, hand signal Low. I scanned the laptop and the program Inssider, not a chance to pollute the channels, but alas a fourth channel, I set up the modem, no other stations, even hidden ones. Signal was -58. Then I crossed my wits that USB ports may not provide enough power, but alas with the ASUS card consumption was 300m, even with TP Linka 500m, ie ports provide the necessary power. In your opinion, where it might be the reason PC in question can not catch people like wireless internet? I thought to call a little more experienced than me, and he told me that was possible power supply desktop PCs to interfere so much wifi signal to mute. After checking again with inssider, this time released a desktop PC, I found that catch significantly fewer routers than the laptop and saw Rezon, though not very encouraging in terms of the above person. -68 Signal had become, I think, should not be a problem. I thought to check out a longer USB cable, just to walk away from the PC card it to see what would happen, but alas it was already 21:30 and just lost interest now to deal with another problem.