The problem at the purple screen showing the Ubuntu logo is usually related to your graphics adapter and the driver being used by Ubuntu.
The best solution is to access your Ubuntu installation using Recovery Mode and install the most recent driver package:
To enter Recovery Mode, hold ESQ when the
Grub loading... message appears so the GRUB menu is displayed.
Ubuntu, kernel xxx... (recovery mode) option.
Choose to mount the disk as read/write, and select:
Drop to root shell prompt with networking
After all the load process finish, type the following commands (one at a time):
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install xserver-xorg-video-intel
If all went well, you should be able to pass the purple screen and get to your desktop.
Configuring the Intel Graphics Media Accelerator 900-950 for Linux [Linux Wiki Guides]
Dell™ Inspiron™ 1300/B120/B130 Service Manual
Dell Inspiron 1300 Review (pics, specs) (points out the graphics card used)
UbuntuUpdates.org - Package "xserver-xorg-video-intel"