It doesn't look like you have enough RAM memory for Xbuntu:

"To run the Desktop CD (LiveCD + Install CD), you need 128 MB RAM to
run or 192 MB RAM to install. The Alternate Install CD only requires
you to have 64 MB RAM. To install Xubuntu, you need 1.5 GB of free
space on your hard disk. Once installed, Xubuntu can run with 192 MB
RAM, but it is strongly recommended to have at least 256 MB RAM.

It seems most Linux distros need or like at least 256mb Ram, but you
can try Puppy Linux which works better from the CD rather than a HDD
install. I use Ubuntu for my modern machines, but for Pentium 3's I
use PCLinuxOS which runs better on those.

Puppy Linux: http://www.puppylinux.org/

And of course there's always DSL, but I can't see how anyone but a
techie would use it, or need it. The graphics remind me of old DOS
screens.

http://www.damnsmalllinux.org/

Well,I think the spesification of your old laptop doesn't meet.The minimum
requirement to run ubuntu or even xubuntu.But I think it meet the minimum
requirement to run fluxbuntu.You should try it ......I think it will run fine...

I get an old notebook, TOSHIBA Satellite 2515CDS and I would like to
run Xubuntu or Ubuntu.
The notebook is Pentium MMX, 32MB RAM, 12Gb HDD, but when I tryed to
"Try Xubuntu without any change to your computer" I didn't succed.

Please I'd like to know how to run Xubuntu without install it over
windows, or if you know any Linux that run into this machine.

I believe you need more than 32 Mb ram to run Ubuntu. Try Puppy Linux or Damn
Small Linux. They can run from a Live CD without affecting what's on the
computer.

I presume you have a CDROM; you didn´t indicate. I had a similar
problem with a Dell Latitude 4100CX laptop. I wanted to install RH
6.0 but had no CDROM. I removed the hard drive, inserted it into a
USB hard drive enclosure and installed Linux to the hard drive
without configuration. Re-installed it in the Latitude and
configured it. I run a GUI desktop, but its very slow. RAM is maxed
at 32 MB and the internal video card is only 1 MB.

As suggested to another forum member you might try Puppy Linux or
DSL. Puppy is leaner that DSL, but both will work. Since I don´t
have a CDROM/floppy unit for this Latitude I will have to install
Puppy via the same method I used to install RH. I know that Dell had
a combo CDROM/Floppy unit for my 4100CX, but finding a working unit
for purchase has been diffucult. Puppy will run with 16 MB RAM. Good
luck if you decide to use this system.

As I told, Puppy worked, but in low resolution, anyway, I will need a
laptop with USB working, this one don't have a USB working anymore...