Power the PC, modem, and router down for several minutes, power the modem up, wait a bit, then the router, wait, then the pc, and then retest the speed. If still slow then try the following. Bypass the router and connect the PC direct to the modem with your cat6. Run some speed tests. If still in the 100 range, check the PC as it may have a limit of 100, may have a bad cable, your modem may have a limit of 100, or your ISP is not giving you the full speed.

@ArcherC8 

Thanks for Replay. 

Problem solved. After inspecting all wires rj45... Found orange wire destroyed. I got 1gbs now. 

I have another problem now lol. After flashing the router wan't star again. A have all light flashing. Iv been trayin unbrick it. But whiteout good results. 

There are several other posts where others have unbricked a router. I never had to. Try some of those things and hope one works for you.

@Dj13france 

thank you, i will do that, hope fix it 

@Dj13france 

 

problem solved ( unbrick C7 )

 

after many test whitout success,

here is solution : 

 

download tftpd32.452

download http://downloads.openwrt.org/releases/19.07.2/targets/ath79/generic/openwrt-19.07.2-ath79-generic-tplink_archer-c7-v1-squashfs-factory.bin ( V1 for me ) 

rename it ArcherC7v1_tp_recovery.bin 

put it on folder tftpd32

change ip address lan computer 192.168.0.66, 

run tftpd

connect C7 to computer lan, press reset button for 5sec ...  after that u will see progress on tftpd. wait 30sec. done

thank for your helping. 

Great... And thanks for sharing the solution.