I have a HP pavilion 751n desktop computer and I accessed the BIOS to change the boot order to have the CD-ROM boot first. Right now my boot order is:
1. ATAPI CD-ROM (Samsung DVD-ROM)
2. Removable Device (Legacy floppy)
3. IDE Hard Drive ( Samsung Hard drive)
4. Other Boot Device.

But, whenever I try to run the burned DVD with Linux my computer first goes to a screen with a flashing line in the top right then goes right to the windows splash screen.

I used Nero 8 to burn the iso onto the DVD, but I used Data Burning. Recently, I found out that you can go to Nero Essentials and then choose Data DVD. Could the problem have something to do with the way I burned the DVD?

What should I do to run Ubuntu off of the DVD?

It does indeed sound like a bad burn. Try burning the .iso again, try limiting the burn speed to 4x (or the slowest available option). Also check the downloaded .iso is not corrupted before doing the burn.

To check if the .iso is not corrupted before the burn should I just scan it with Windows Live OneCare?

Also,how do I limit the burn speed to 4x and how do I make sure I'm just burning the .iso in Nero 8?

"To check if the .iso is not corrupted before the burn" - No. You need to calculate the MD5 sum of the ISO, and compare it with the actual MD5 sum. The actual MD5 sums should be available from the Ubuntu download page. Google Windows MD5 sum if you need help with this.

I used the Nero Infotool to check the write and read speed and the read speed is 24x but can go as low as 4x but the write speed is only 24x and no other options. Can I still change the burn speed?

Also, the dvd I am using is a DVD +R DL. Could this be contributing to the problem? Is the dual layer dvd not compatible with my HP Pavilion 751n desktop computer?

Welcome to Linux Questions.

Not at all to be burned as a Data DVD,
but to be burned as an image.!

It is an " .iso file ", isn't it ?

Good Luck.

USE ISO BURNER TO BURN THE DVD

download and use imgburn ( thats if your using windows) its free and a very small program burn at a slow speed

Burned it correctly with infra recorder, but now when I try to boot it from the live cd, it freezes at the ubuntu splash screen.

What can I do now?

Just try again with Nero, the function
"Burn an image file" or "Burn a picture file"
(depending on your language) is not impossible
to find.

Or use the tool suggested by Shadowmeph.

Regards

Got it to work by changing the boot option to napicol and I was about to start transfering my files to a hard drive when it froze.

What do I do

Can you be more specific. Transfer what files? From where?

My documents, movies, and music. I'm trying to transfer them from "My Computer" in Places in Ubuntu.