I'm trying ubuntu. I checked the hash on the ISO I made on the disk, and it's right, but I'm not sure what problem I'm having. First, I'm not sure I burned the CD as an image. Second, I've been unable to partition my hard drive because windows is in Spanish. Whenever I try to boot the computer after telling the BIOS to prioritize the CD-ROM, it just opens Windows as if there was nothing in there. When I give priority to the CD and nothing else, it says there's a disk error and that I need to put the system disk in.
Sounds like you copied the iso file onto a CD rather than actually burning an image. I believe Windows, can't do this on it's own. Download a burning program such as this open source one: http://infrarecorder.sourceforge.net/
If you can boot from other bootable CDs (for example a windows install CD) then it looks like you haven't burnt the disc correctly. If you can't boot from any bootable CDs then there is something wrong with your setup (on the hardware/bios side)
Yes, it seems like your cd has some errors (maybe it wasn't burnt ok, maybe the downloaded file is bad and you have to download it again). If you can't start the cd, make another bootable cd or download the image again. (Remember you have to create the image with the iso, not just create a cd with an iso file inside of it.)
If you do that ok, you'll be able to boot from the cd. Once you get to boot it, choose the option that lets you do a check on the entire cd, so you are sure there aren't errors on it (so there are no broken packages, and that kind of thing). Only after that, start the live cd, and then install from there.
There are a bunch of freeware CD-burning apps that can burn an ISO for you if you don't have Nero/Roxio; CDBurnerXP comes to mind. Once you are able to boot, just let Ubuntu load into the LiveCD OS. From there you can use the built in partition editor to resize your main partition and just have the installer fill up the empty space.
What's most likely the problem?