Media Audio Contoller problem

[NancyS]

I have sorted out most of the problems on a young friend's computer who went crazy uninstalling things she didn't know the importance of...except for this problem.
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Her computer has no sound from any source. It is 6 months old and it has worked flawlessly until she screwed with it. This box was custom made from a reputable company.
In Device Manager, listed in Other, is Multimedia Audio Controller, with a yellow ? mark.

At each reboot computer tries to install drivers, but fails saying there aren't any. (she probably deleted these I assume)

I've read many similar threads on this subject on this forum, but am still stumped, hoping someone can help. I don't know if she has a sound card or onboard (and she certainly doesn't know), but per another post I downloaded the aida32 program and it disclosed...

Motherboard ID = 1/20/04 SpringdaleG-6A79AE19C-00
Motherboard Name = ECS 865G-M (deluxe)/PF2

under PCI/PnP Audio Icon...
Intel 82801EB ICH5 - AC ' 97

I would be so grateful if you could help me out with this.
Nancy

edit---she is running XP Home

2nd edit----she discarded all CDs which came with her computer <sigh>