Second-generation (2000 series) i3 and i5 only;  8 G max.

Memory can be purchased just about anywhere.  These CPUs are pushing 10 years old - you'll likely find them only second-hand by auction (EBay, etc.).

Batteries will likely be all third-party;  search online for a reputable seller.

Welcome to the Dell Community @Asif256 

Lets start with what I was able to test today.

8GB max ???

@ejn63 sorry to say wrong.

Vostro 2520 max ram 16GB "BIOS Detected it."

And W7 detected and utilized it.

Sorry @Asif256 but I did not have time to find the best i7 CPU today.

I will continue testing on Monday if you want the correct answer and the best CPU for yor laptop!!!

Best regards,

U2

@Asif256 

If you are still interested yes you can install i3, i5 and i7 CPU's!!!

I installed an i7-2640m and it is performing great.

It is the same CPU I use to upgrade my E6420 XFR's

So it is confirmed 16GB memory and i7-2640m CPU.

As far as pricing and location to purchase without knowing your location, your on your own.

Good luck,

U2

Can U specify RAM parameters?
{ sth like: 8GB DDR3 2Rx8 PC3L-12800S-11-13-F3 1600MHz & 1.5 Volts or maybe works sth different like: DDR3L PC3-12800 -11-11-11-28 & 1.35 Volts etc, ... }

Quote from Asifa256

"Hi Team,

Could you please confirm can i upgrade my laptop process from i3 to i5 or i7? 

Also what is the maximum RAM and SSD drive can be supported?

Please send all the details with price to me.

Also the price my the laptop battery and from where i can bought all these."

Hello,

I never heard of a vastro computer.  

It be better off you purchase a new computer.

In regards to upgrade to ram and specs look it up yourself  why do you need the dell team or ask someone to do the work for you do it yourself it is not difficult to do. 

Great, 16GB RAM confirmed, but at first glance is OK but each 1GB of RAM generates power 1watt. Thus if installed 8GB it means that generated is 8 watts of heat while there is 16 GB gives 16 watts. The question is if such of amount of RAM does not create overheating problems? Thinking because there is not present some equipment under the keyboard, where RAM present, to directly remove excessive heat.

Glad, I found this thread @U2CAMEB4ME  My system is also Vostro 2520 but with intel Pentium 2020m and in user Manual it say max 8GB ram.

1. Will it work if i install 2x8Gb DDR3 1600Mhz ram instead of preinstalled 2GB ram with similar config.

2. Are all Vostro comes with same Motherboard, BIOS and Socket.

3. Is it possible to install i7 2640m in my system having Pentium. If yes, where can i get this processor in India.

Thanks for posting the valuable info.