Gmail running slowly

[Edsterr]

After a few minutes of use, gmail starts to run slowly. When I close and reopen it, it will run normally for a few minutes but then go back to running slowly. I usually use Chrome, however I checked and the problem still occurs with IE, Firefox, and even Opera. It is the only thing running slowly, and it only runs slowly on this computer.
Any ideas on how to fix it?

 

[BK_123]

Run your antivirus and antimalware scans to see if they pick anything up, Also run give CCleaner a run as that will clean out a lot of junk that is hiding..

 

[Edsterr]

I had already tried running antivirus, with it showing that nothing was wrong. Having just used CCleaner, Gmail continues to run slowly.

 

[BK_123]

Run a Speedtest and see whats speeds that machine is getting. Is it near your router?

 

[Edsterr]

It's connected to the router via cable, and I'm getting 100 down/10 up

 

[BK_123]

Can we just confirm that by running a Speedtest here Speedtest.net by Ookla - The Global Broadband Speed Test and putting the result here..

 

[Edsterr]

Sorry, I don't currently have access to the computer, but I don't see how it could be a problem with the router anyway. The only thing running slowly is gmail, and it is only running slowly on this computer, it's still fine on the laptop which is connected to the same router as the pc

 

[BK_123]

When it is running slow what browser are you using and have you tried using a different browser?

 

[Edsterr]

Normally I use Chrome, but the same problem persists in IE, Firefox and Opera

 

[BK_123]

Is there any toolbars & unknown extensions installed in Firefox & Chrome, Also check Add/Remove Programs for toolbars..