My Computer(please see above message also.

20140938-177x150-0-0_E+Machines+etower+733i+ETOWER733I.jpg

Thanks for the info. If you wish to upgrade your PCI card you need to upgrade the PSU as well.

All cards of 256MB RAM will require a minimum 300 watt PSU.

Again the cards at Newegg:

Newegg.com - Video Cards & Video Devices,Desktop Graphics / Video Cards,PCI,

PSU:

Newegg.com - Computer Hardware,Power Supplies,Power Supplies,400W below,MicroATX,

This is a cheap one specified for eMachine:

Newegg.com - Athena Power AP-MP4ATX30 300W MicroATX/SFX-12V ATX-12V eMachines, HP Upgrades/Replacement Power Supply - Power Supplies

This is more expensive but again specified for eMachine:

Newegg.com - Athena Power AP-MP4ATX47FE 470W MicroATX / SFX12V / EPS12V / ATX V2.2 eMachines, HP Upgrades/Replacement Power Supply - Power Supplies

Cheap PSUs are not recommended highly but as they say you get what you pay for.

At least a 300watt power supply to upgrade to a 256mb graphics card....Huh? Will installing such a power supply have an adverse effect on any other part of the computer(motherboard....other cards....or whatever)? Stevo

Modern graphics cards are the largest wattage draw on a computer.

As long as the PSU has been specified for your system there should be no issue with the other components.