Why can't my computer handle 24 tracks of audio?

[cash]

Here's the problem. My computer cannot play back 24 tracks of audio. It says I am maxing out either the cpu or the disk. This is why I am confused. I had to take these 24 tracks to a friends house for a session today and his computer played them back flawlessly. His cpu meter never got over 16%. But his computer is 200 mhz SLOWER than mine. Do I have my computer configured wrong? Any help would be appreciated.
Here are my specs. 933 pentium, 256 meg of ram, 40 gig hd for audio. I have the motu 2408 mkI with wdm drivers, 11ms latency (although I tried all the others), 64 meg buffer. It is a dedicated music computer. I am running Sonar XL.

[Queue]

How fast is the HD?

How full is the HD?

Have you defragged lately?

DMA enabled on the HD?

Windoze 2000?

Queue

[cash]

The hd is 7200 rpm, and I've got 56% of the disk left. I just defragged a couple of days ago. What is DMA? I'm running Windows ME.

[Queue]

Right click "My Computer" and choose "Properties"
Click the "Device Manager" tab at the top.
Make sure the "view devices by type" radio button is black
Click the + sign next to "disk drives"
Right click on the Audio Drive, choose "properties"
Click the "Settings" tab at the top.
You should see a "DMA" checkbox, it should be checked.
If it isn't checked, do so, restart and repeat to make sure it stays checked after restart.

Queue

[cash]

Man, you are a god. I can't thank you enough. You totally made my night.