youtube is lagging my system

[m7mod]

recently did a clean install to windows 10 from 7 , i watched couple of youtube videos on chrome after that every time i want to watch a video it lags and put my whole system on 5fps the mouse cursor and the audio becomes like a slow talking robot , when i restarted my laptop it worked but again after some videos it happened again i tried it with microsoft EDGE but it's the same of course it works every time when the white bar in youtube video if fully downloaded by works i mean it was better i happens once or twice , i tried downloading some videos it was better (like when the white bar is complete)
what i tried
-upgrading my drivers ( went to nvidia and installed the least drivers ) and bought an license to an driver upgrader and fully upgraded my drivers
-tried with and without hardware acceleration
-tried a different browser
-watching on a low quality even on 144p
-scanning and cleaning with viruses with bitdefender TS 2016
-scanning and cleaning for malware with ADWcleaner
my specs
i5-4200u
6GB ddr3 1600mhz
nvidia geforce gt740m
toshiba L40-AT27W1 laptop
speed test : 10mbps DN an 5 UP on wifi though it suppose to be 20 but i think it is the speed test because it uses flash
speed test : 20mbps DN and 10 UP on LAN it suppose to be 50 but i think it is the speed test because it uses flash because using it it also lags the system
i tried the speed on another laptop and it gave me the correct speeds
my cpu usage with 720p60 video was around 50% and my ram around the same so it's not hardware
what to do it's really annoying restarting my lap every time after watching some videos on youtube or even dailymotion (i know nobody uses that but i wanted to try it was the same)
sorry for the bad grammer

 

[netyoda]

6GB of RAM is NOT a lot of memory. I would suggest a MINIMUM of 8GB, if not 16GB. Watching YouTube in any browser will eat up memory. You see 50% memory usage as that is what the OS throttles to, so the system does not freeze up. If you had 8 or even 16GB of RAM, it wouldn't go over 50% except when it spikes. Run Task Manager while you have YouTube loaded and check how much memory is actually being used by the Browser. If you can get more RAM, it can only help you in this and many other situations.

 

[m7mod]

6GB of RAM is NOT a lot of memory. I would suggest a MINIMUM of 8GB, if not 16GB. Watching YouTube in any browser will eat up memory. You see 50% memory usage as that is what the OS throttles to, so the system does not freeze up. If you had 8 or even 16GB of RAM, it wouldn't go over 50% except when it spikes. Run Task Manager while you have YouTube loaded and check how much memory is actually being used by the Browser. If you can get more RAM, it can only help you in this and many other situations.

the total RAM usage is 45% while i'm watching 1080p60 with background stuff video and the cpu is 25% it's not my resources it was working fine in windows 7 , 6GB is more than enough for youtube

 

[m7mod]

it was bitdefender firewall , i just turned it off and it is working

 

[USAFRet]

MERGED QUESTION
Question from m7mod : "youtube is lagging my system"

recently did a clean install to windows 10 from 7 , i watched couple of youtube videos on chrome after that every time i want to watch a video it lags and put my whole system on 5fps the mouse cursor and the audio becomes like a slow talking robot , when i restarted my laptop it worked but again after some videos it happened again i tried it with microsoft EDGE but it's the same of course it works every time when the white bar in youtube video if fully downloaded by works i mean it was better i happens once or twice , i tried downloading some videos it was better (like when the white bar is complete)
what i tried
-upgrading my drivers ( went to nvidia and installed the least drivers ) and bought an license to an driver upgrader and fully upgraded my drivers
-tried with and without hardware acceleration
-tried a different browser
-watching on a low quality even on 144p
-scanning and cleaning with viruses with bitdefender TS 2016
-scanning and cleaning for malware with ADWcleaner
my specs
i5-4200u
6GB ddr3 1600mhz
nvidia geforce gt740m
toshiba L40-AT27W1 laptop
speed test : 10mbps DN an 5 UP on wifi though it suppose to be 20 but i think it is the speed test because it uses flash
speed test : 20mbps DN and 10 UP on LAN it suppose to be 50 but i think it is the speed test because it uses flash because using it it also lags the system
i tried the speed on another laptop and it gave me the correct speeds
my cpu usage with 720p60 video was around 50% and my ram around the same so it's not hardware
what to do it's really annoying restarting my lap every time after watching some videos on youtube or even dailymotion (i know nobody uses that but i wanted to try it was the same)
sorry for the bad grammer

Is your PC multi-GPU? If so, try going to Nvidia control panel and putting your browser to RUN WITH NVIDIA card instead of integrated card. I had lots of crashing on my HD i5 530 but when I switched my Firefox to Nvidia, no crashes at all

it was bitdefender firewall , i just turned it off and it is working