If you played that game before any lag before it makes no sense to splash cash on SSD, what i would suggest would be:

1, instal GPUz (select the Nvidia card as the one you want to see in program) and check you temp under load, you can thick box "save log to file" and after you notice the lag, you can check the record in txt file and see if the temperature on GPU isnt to high, i mean more like 80-85 because if it will go that high you GPU might underclock and that will cause those lags, you will see what frequency you have when graca is running on normal temp and if the frequency drops it might be overheating - you cal solve it by using compressed air check some videos on youtube how to do it.

If you are not sure how to use GPUz check also youtube for how to.

2, run the short diag on your pc - turn on the system and keep pressing F12 while dell logo is displayed, then choose option diagnostick or ePSA (depends on system)

3, one more thing, when did your problems started? 

Marian

I would advise upgrading the hard drive to a Crucial MX100 SSD and clean installation of Windows 7.

For more details see Windows Reinstallation Guide/A Clean Install of Windows 7:

http://dellwindowsreinstallationguide.com/a-clean-install-of-windows/

I just did another dell diagnostic test. 

I am getting the following errors:

Error Code 2000-0123

Validation 23330

Msg: Memory-integrity test discrepancy

Any new advise? Is this the cause of my slowdown in my laptop performance?

Thank you

It very well could be the cause.  Unplug the system, remove the battery and remove and reinstall both memory modules.  Re-run the diagnostic test, noting which module shows bad.  Swap the two modules - if the error follows the module, the module is bad;  you will need to replace that memory module.  If it sticks to the same socket when the modules are swapped, it's the socket that's bad and you'll need to replace the mainboard.

Yes, as the other guy sugested its memory problem, 

also good step would be to x test memory.

Test RAM #1 in both slots separetly then

Test RAM #2 in both slots, 

basicaly you have to run the same diag 4 times to find out if problem is cause by one memory or slot for the memory.

But as he already mentioned it might be just loose memory as you were moving with the pc while usage, we had these cases already before.

If you are not comfortable with x-testing memory, ask some of you friends, but its nothing compicated, main thing is to remove ACAD and BATT before opening pc and also press and HOLD power button before touching anything. If you are not sure how to open pc, you can find manual on dell.com after inserting your service tag or search for youtube video where they open same pc as you have, pretty easy.

Let us know how it goes, btw your pc can easily run on one memory module only. Depends how much memory you have. For example i have 16GB but i could easily live with just 8 but there was no option to choose less ;)

Hello Zota, 

If your pc is under warranty you can still open it until you dont break anything inside. If you are not entirely sure that you are skilled enough you can always give them call and they will guide you over the phone.

good luck and let us know how was your problem resolved.

Marian

Replaced the motherboard and ram. 

The game still lags. 

So I restored the PC and updated the drivers.

It appears to be working fine for now.

The games lag again. 

I am going to try clean installation. 

If this does not work, the next laptop that i am going to buy is not a Dell. 

Tired of troubleshooting this issue. 

Hi. I think its caused by something what u installed after the restored pc. Try to think about it and u should find it. When i had problem with laging i tried everything and at the end i found that was the router what causer my problem. The weirdest thing was that i had tried another router at my place because i have spare one at home and it was the same... my solution was that i had to reset my wifi router to make it work again. Did u try it(but i mean hard reset and set up new password again and same with network name. Usualy u do this with button in the back and u have to hold it like 15 seconds-check ur wifi router manual)? Sorry for late resonse but i am now on sommer holiday ;)

If that was the case, this is really so tiring. 

I going to do a clean installation first. 

In that case, i can't install anything then. The laptop will be just a word processor laptop. 

The things that I installed are just the drivers and the usual common software like chrome. 

I did a clean installation. 

It stills lags after i installed Starcraft 2.

I give up. 

My laptop is still under warranty. 

Is there something Dell support can do as it appears that the hardware seems to doing fine. 

Spoke to the dell representative who reckons that my PC is overheated, I am going to the fan and heat sink replaced. 

I hope this is the problem.

I am still facing lags. 

I have changed the followings:

-motherboard

-Fan

-ram

-Screen. 

It appears the only major item left is the hard disk.

Why can't dell just replace my whole laptop?

I am so tired that I think I will just use this laptop to browse the internet.