The 5742G graphics card is not a card but chips on the motherboard. And as you know, motherboards are not cheap or swapped in most laptops.
http://www.notebookcheck.net/NVIDIA-GeForce-GT-420M.35837.0.html shows it was respectable for games of its day.
Hi guys and girls,
so as the title says. I have the following machine:
Operating System
Windows 8.1 Enterprise 64-bit
CPU
Intel Core i5 480M @ 2.67GHz 42 °C
Arrandale 32nm Technology
RAM
8,00GB Dual-Channel DDR3 @ 532MHz (7-7-7-20)
Motherboard
Acer Aspire 5742G (CPU)
Graphics
Generic PnP Monitor (1366x768@60Hz)
1023MB NVIDIA GeForce GT 420M (Acer Incorporated [ALI]) 45 °C
Storage
111GB KINGSTON SV300S37A120G (SSD) 32 °C
465GB Western Digital WDC WD5000BEVT-22ZAT0 (SATA) 31 °C
Optical Drives
No optical disk drives detected
Audio
High Definition Audio Device
I can provide additional information regarding motherboard:
Motherboard
Manufacturer Acer
Model Aspire 5742G (CPU)
Version V1.04
Chipset Vendor Intel
Chipset Model Havendale/Clarkdale Host Bridge
Chipset Revision 02
Southbridge Vendor Intel
Southbridge Model HM55
Southbridge Revision 05
BIOS
Brand Acer
Version V1.04
Date 11.8.2010 г.
PCI Data
Slot PCI-E x16
Slot Type PCI-E x16
Slot Usage Available
Data lanes x16
Slot Designation J5C1
Characteristics PME, Hot Plug
Slot Number 0
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J6C1
Characteristics PME, Hot Plug
Slot Number 1
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J6C2
Characteristics PME, Hot Plug
Slot Number 2
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J6D2
Characteristics PME, Hot Plug
Slot Number 3
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J7C1
Characteristics PME, Hot Plug
Slot Number 4
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J7D2
Characteristics PME, Hot Plug
Slot Number 5
Slot PCI-E x16
Slot Type PCI-E x16
Slot Usage Available
Data lanes x16
Slot Designation J8C2
Characteristics PME, Hot Plug
Slot Number 6
Slot PCI-E x1
Slot Type PCI-E x1
Slot Usage Available
Data lanes x1
Slot Designation J8C1
Characteristics PME, Hot Plug
Slot Number 7
Is it possible to change the video card of this lap top?
Thanks!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic