My Laptop has Intel integrated graphics. Is it possible to buy an Nvidia graphics card and add it in a laptop? I'm not sure if there will be additional slots in a laptop.
Lenovo - Y410
Laptops are quite a bit different than desktops in the sense that every laptop motherboards vary in shape and are limited in how much they can be upgraded.
This isn't really going to help much, but the answer is Yes and No. The video processor may not be removable (thus requiring switching out the motherboard, which obviously means you might as well just buy a new laptop).
First it would be good to lookup your model (for example, on Lenovo.com), and find out what the highest graphics processor available to your model is. This is the safest bet as your motherboard should have no problem supporting the upgrade (to the specific graphic processor models available on the manufacturer's model lineup)
However, having had a Lenovo Y530, I believe my video processor was removable. I have a semi-complete tutorial on disassembling a Lenovo Y530. I'll try to dig it up and post up the additional details.
-- So I dug up my photos from my Lenovo Y530 disassembly and I can't confirm whether its removable; however, from the looks of it, it is. I attached (2) images. The black heatsink is where the video processor is while the other image is of the CPU processor (with heatsink)
Your laptop probably has an Expresscard port. There are video cards available for this, but they're certainly not common. There's also this goofy kludge: http://sewelldirect.com/ViDock-2-ExpressCard-External-Video-Card-Solution-Empty-Chassis.asp
I wouldn't recommend either of these though, and I certainly wouldn't recommend popping open the laptop and replacing it that way.