This is an almost 10 year old laptop. How much RAM do you have installed (the maximum amount is 8GB of DDR3). Do you have an HDD or SSD? With an older system the ability to increase performance is limited and may not be worth the cost. It may be time to start thinking about replacing the system with a new much faster laptop.

I foolishly bought 2 of these laptops, one for a family member and neither works properly or ever did actually but at the time I was not in a place I had time to do what needed to be done.  They should have been returned. I didn't believe that Dell would sell something so inferior so I kept trying to work with it.  I finally took it to an expert and he told me the bad news. These machines were build in a way they would never perform better because of their components and there is no fixing that would change this pathetic machine. He explained it technically, but I can't duplicate that explanation here. Had to believe him because everyone who has this computer will say the same thing about them, they're awful. Consequently I never bought another Dell product.  Shame on a company that would scam customers so brazenly.

Hello I apologize for the late reply. I know the laptop is old and if I could afford it at the moment I would have gotten a new one. In any case, the installed RAM was 8 GB increased a few weeks ago thinking of increasing the performance a bit, now I have solved it by putting a 500gb SSD.

@peppeb 

Yes, you can.

https://en.wikipedia.org/wiki/Dell_Latitude

Regards,

U2

Welcome to the Dell Community  @peppeb  and  @havirim 

If you know what you are doing, then the E6420 should run W10 with no problem for years to come.

Like @peppeb , adding an SSD is one of the best options for increasing the performance.

After that you still have a few options.

CPU upgrade: Upto the i7-2860QM

https://www.cpu-upgrade.com/CPUs/Intel/Core_i7_Mobile/i7-2860QM_(PGA).html

Memory upgrade: 2x8GB for 16GB total

Next would be 2 software tweeks.

Advance System Options set to "Adjust for best performance"

Then increase the "Vertual Memory" to double the reccommended size.

Best regards,

U2

Thanks for the solutions, last week I bought a 500gb SSD and at the moment it seems to have improved a lot, unfortunately the RAM more than 8GB I can not put, I will check if I can put the processor you recommended. Thanks again