I can boot from a Slackware DVD perfectly... The problem is that I have two 500GB harddrives (no raid, just SATA) and it doesn't find either. I can boot into Vista perfectly and all my hardware works. I went into the /dev folder and found hda-hdt but none of them were right. Also, there are no SD(a-z) in the folder at all.
My Mobo is Gigabyte GA-EP45-DS3R
Note that I haven't gotten linux to work at all on the machine except the Slackware installer. Also, the DVD can find flash drives if I can load drivers from there.

Hi,

Welcome to LQ & Slackware!

What do you mean it doesn't find either? Which kernel are you attempting to use from the dvd? What about the md5sum for the iso, check it with the original iso? What about the burnt DVD image, did you compare that with the md5sum of the original iso md5sum?

How do you have the BIOS setup for the SATA & IDE?

First, I would like to say thank you for responding so fast and taking your time to try to help me.
I meant both of the harddrives.
hugesmp.s but I found that huge.s has the same results. I haven't tried any switches or parameters yet.
It's valid. I used an md5 program on the iso and checked it with the one on the mirror. they matched. Also, I used ImgBurn which automatically checks the disk with the ISO.
The drives are plugged in by SATA cables. The BIOS says:
"SATA RAID/AHCI MODE [Disabled]
SATA Port0-3 Native Mode [Enabled]" <-- I'll try changing that and see what happens
The IDE controller is also enabled, but nothing is plugged in.

Are you sure it doesn't see them ? If you are sure of this, try changing enabling AHCI mode.

Hi,

I won't rely on md5sum checks by any burner applications.
If you downloaded the cd/dvd iso then be sure to check the md5sum for the original iso. From the cli;

This will check the download iso with the known md5sum that you also get with the iso.

You could have a bad burn, to check the cd/dvd with the original iso md5, use this CdromMd5sumsAfterBurning.

A little work on your part to check the cd/dvd to original iso but worth the effort.

This link and others are available from 'Slackware-Links'. More than just Slackware® links!

From the Review of this motherboard on Phoronix

so your most likely issue is a kernel issue. you need an installer with a 2.6.26 kernel or newer.

according to the info on Distrowatch it looks like you would probably need to use the slackware-current installer, or create your own custom 12.1 install iso using a kernel you compile..

slackware 12.1 = 2.6.24.5

slackware-current = 2.6.27.5

This was the correct answer.
Thank you to all who tried to help.
Unfortunately, I could not get my hands on a kernel newer than 2.6.24 as I did not have linux on any computers, and thus had no easy way to compile it.
Also, I used a separate md5 checker to check the iso against the website and only used the burner to check the disk against the iso.
Once again, thank you to everybody who responded. Up to this point, I never really used Linux much, so it will be great to finally have a working system to try it with. (I am not a total newbie though, I have worked with DSL and Ubuntu. The first was too outdated for the hardware, and the second one was too bloated(not to insult Ubuntu users, I just didn't like the experience))

Actually farslayer was correct too:

This is a true statement. Lower kernel versions do not have the SATA drivers for that SATA controller. However, you can actually bypass this if you put the controller in AHCI mode. This way you only need the AHCI driver which should theoretically work with any AHCI compliant SATA controller.

Anyway, glad to see it worked.