Online games not functioning on one pc on network. All other devices normal.

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Windows 7
TP Link Router TL-WR841N

This problem started a few days ago.  It started intermittently but it has worsened and is now constant.  I start an online game and when I press a control there is a delay or just no response.  Or it works for a few minutes, then problems start back up again.  It is only on my computer, which is custom built with a MSI Motherboard I-5 Intel processor and Nvidia 660 graphics card.  Other devices on the network are working fine, particularly one other desktop which is constantly running online games with no issues.
I constantly run speed tests with good results.  Currently 46ms ping, 15.88 Mbps download speed, and 5.15 Mbps upload speed.  The speed is capable of going higher but I limit it to allow for equal use over all devices on the router.
I have tried shutting off antivirus and disabling windows firewall.  I have tried adjusting the wireless settings on my router (changing the mode and channel).
I am unable to do a system restore because my computer is not saving system restore points for more than a day or two.  (Another problem, but not the current issue.)
I am no computer expert, but I manage to get things done normally.  But at this point I am at a loss.

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Well no one answered this post but I will tell my solution anyway.  I am not going to go into detail of how someone did it, but someone was messing with my connection.  I am 99 percent sure it was someone else that used my network (because of my findings).
Like I said, I don't want to go into detail of how they did it, because I don't want other people learning anything about it to do it to someone else.

But the solution was to change my MAC address, and I will keep changing it if and when the problem pops up again.
So before you try reinstalling windows, and any other solution try changing your mac address first.