A fresh install from the Ubuntu disk does not include the wifi and webcam drivers by default, so you have to install them manually. If you can connect to the internet by ethernet (wire) from your laptop then do so.
If you can connect by ethernet
Go to System -> Administration -> Software Sources -> Updates tab.
Check the box saying “Unsupported updates (hardy-backports)” and close the window.
Open a terminal window and type
sudo apt-get update
and then
sudo apt-get install linux-backports-modules-hardy
This is a meta-package that will install the relevant modules for your kernel version and keep them up to date whenever you install a new kernel version. After a reboot your WiFi and/or webcam should work now, and hopefully bluetooth but I’m not sure whether these modules will enable bluetooth or not.
If you cannot connect by ethernet
Go to the following page and download the file for your processor (AMD or Intel) to a removable storage device (eg. Pen drive). The file you want to download is under the header “Download linux-backports…” from here
Put the pen drive into your laptop and double click to run the .deb file you downloaded from that page. Install the package (you’ll need to use your sudo password).
After that, a reboot should have your wireless and webcam running (if you have a webcam). However, you should now do all of the tasks listed under “If you can connect by ethernet” before any new updates. This is because kernel modules are kernel version dependent, and you need the meta package to ensure your kernel module is kept up to date with any new kernel versions.
Sound
Sound should be working with the default Ubuntu install on an Inspiron 1525, but with some limits, namely Pulseaudio won’t work with all programs installed on your computer so you might be limited to only one application being able to produce sound at a time.
For a simple solution, just open Synaptic, search for “Pulseaudio” and install all the packages it lists.
You may not need to, but it may be best to reboot after installing these pulseaudio packages, to ensure the server and your desktop environment loads all of these new packages and uses them.
More: continued here