You can't get by 1st. base on the Gateway website without these 2 identities:
1: Desktop or Laptop?
2: What is the Series name?
I went thru the list thoroughly and failed to find any match for "nmz500se" but after doing a bit of Googling, I discovered that you actually have a Desktop/Tower model E-2000
(which conveniently is not listed on the Gateway website). I don't know where you came up with "nmz500se".
So I need some additional detective work from you. Open Device Manager, find the Graphics/Video Adapter (it may be listed under "unknown devices"), double-click it, click the Details tab, select "hardware id" and give me the "hardware id string" that begins with PCI\VEN (1st. line of text only).
Or..... provide a physical description of the graphics/video adapter card including the main chipset name and number. What you provided was a partial/invalid computer description (not a graphics adapter at all).