Dell Optiplex GX620 OSX 10.5.7 sound issue

My first post here and very new to the MAC world.
Installed OS X 10.5.7 on my Dell Optiplex GX620 using instructions I found specifically tailored for my machine. That in itself blew me away!

However, while I have most things apparently working (this post is being done via my iPC), I'm trying to get the sound working.

Now, I had this working last week after doing a bunch of searches on the net and doing a bit of Sherlock Holmes. But yesterday when I started the machine and got the dreaded circle with slash line at boot-up after several attempts, I decided to just reinstall the whole thing again. Big mistake, since now I know why it was freaking out (the keyboard not being recognized).

Anyway, this time out I'm not able to find what I did to make the sound work. But at least I know my files downloaded are correct as they worked before.

So here is where the hickup is happening.

In Terminal, I'm to enter the following lines:

sudo -s
chown -R root:wheel /System/Library/Extensions
cd /System/Library/Extensions
chown -R AppleAC97Audio.kext

I found that last line is not correct, as a USER is required. So I changed it to the following and it worked.

chown -R root:wheel AppleAC97Audio.kext (if this is wrong, please tell me)

cd /System/Library/Extensions/AppleAC97Audio.kext/Contents/PlugIns/
kextload AppleAC97AudioIntelICH.kext

That last line gives an error. So I ran it again with the -t and got the following:

"com.apple.driver.AppleAC97Audio = "
"No valid version of this dependency can be found."

I'm stuck. Please help.