When i play games internet disconnect troubleshoot says: Ethernet cable is unplugged

[ice demon]

So first sorry for my bad eng
This problem started before 1-2 months
when I play online games(sometimes this happen when I watch youtube in full screen) I can join to server and have 2-3 seconds to play - after that internet will disconnect
If I press troubleshoot problems it say that ethernet cable is unplugged
I can have back connection if I go to device manager then to my driver (Gigabit PCI express network adapter) > Advanced > speed and duplex and to change to any value or to network and sharing center > Change adapter settings > and then press disable and after that enable
I tried almost everything that I founded on net: changing speed and duplex , changing ethernet cable , scan for malware/virus , unplugging power cord etc.
I use wired connection , but my sister can connect to router(while I dont have connection)
I dont play newer games , I play games like Tf2 , CoD4 etc.

My ethernet card is TP-LINK TG-3468
Router: TP-LINK TL-WR741ND
Pls help I am gonna to throw Pc from terrace

 

[EndlessWaves]

Have you tried your motherboard's built in ethernet port?

Have you download the latest drivers for your ethernet card?

 

[Davek]

Get a new ethernet card

 

[ice demon]

Have you tried your motherboard's built in ethernet port?

Have you download the latest drivers for your ethernet card?

I bought a card before about 50-60 days, other ethernet port is dead after a lightning strike (This problem is also happening on it)

Yes I download latest drivers

 

[ice demon]

Problem is now worse when I start programs not just games connection gonna "die"