Surfing Internet The Wireless Adapter Just Turns Off?

i am having a weird wireless adapter problem. first of all the model of wireless adapter is tp- link ( tl-wn722n 150mbps ) and i am connected to tp-link router ( tl-wr740n ). so for the problem it's whenever i am surfing internet the wireless adapter just turns off.. it's either it's stuck on green light or no light ( it flashes green every 2 seconds when its normal ) sometime i can stay on the internet for 1 minute to 5 hours, but it's mostly few minutes. i noticed when i am reading news on internet or something like that it doesn't disconnect, but when i turn on Internet and watch a vid it suddenly drops signal. i have to unplug and plug it in again to get the connection back.

i have tried alot of things..i have changed ports,reinstalled all drivers in router, updated drivers, restetted settings to factory defaults, changing security, channels..nothing worked. the signal is pretty good i can still download with at least 1mbps of speed + the signal bar is full or 1 lower. another weird thing when i am downloading a file it doesn't dissconect i think it's just fine when i'm away from the computer.. but when i start googling,chatting on steam watching videos it just looks like it lost signal or something. also this is not the wireless adapter, because i had one before it started having same problem.. i bought this one at start it had same problem but it was 1 day, but after 2 weeks it started happening.. it's not overheating, i can be connected to internet in safe mode without a problem. also i am using a pc not laptop there are no viruses or malwares on my computer i have used avg and norton antiviruses for scanning, i also got 2 other computers one is loptop and other is pc none of them got such a problem.