Lost Display settings for monitor after graphics update from windows

hi,

i have a good friend who has a Dimension 4600 desktop, about 6 years old.  she has windows xp home OS and just realized that

she has not done any  windows updates for years!  well, i was helping her get all her updates installed and it took hours.

one of the hardware updates that popped up was for her Nvidia GeForce MX graphics.  her computer came with a Dell E171FPb flat monitor

and was working fine with usual 1028x7?? setting and high color(16) I believe.  i checked her graphics card from her purchase invoice and

found it was a Nvidia GeForce MX card.  the update said Nvidia Geforce MX 440 w/AGP 8x.  i figured it was the same or else Win Update wouldn't

have suggested it.  anyway, installed the update and after the restart she lost the monitor(display) settings she had, and now it is in Low 4 color, at

800x600 and cannot be altered to handle higher resolution.  cannot move the settings and there are no other options available.  ive tried to reload

the original drivers from dell web site and from the original resource cd.  nothing works.  she cannot use Window XP appearance without getting a

blurry screen.  using Hi contrast settings are better but it looks like windows 95 and the internet is terrible.  What must be done to get the display

setting back to their original state?  where she has options in resolution and color schemes?  was this update to nvidia a mistake? any clues please

before i have to contact tech support?

thanks

Bill