There is (or was) a Dell recovery partition on the hard drive, accessed by F8 at initial bootup that will restore the PC to the original factory condition.  However, installing Linux probably corrupted that partition and it's no longer available (but try it to see).   On a manual install the correct and required install sequence is (1) Install Operating System (2) Install Dell Laptop System Software (3) Install motherboard Chipset Drivers (4) Install Device drivers such as sound, video, ethernet, etc.   The chipset drivers, which must be installed BEFORE installing device drivers such as the sound, are key to  a successful install as one of the prime things they do is define (identify) all the hardware devices on the motherboard.  The chipset drivers are the most often skipped item.   The Dell invoice that you got with the new PC details everything that is in the PC.  However, accessing the drivers using your service tag number should get you what was installed on the PC and not optional items. HERE is the Dell reinstall instructions. 
I received a brand-new Studio XPS 16 laptop for Christmas. After attempting to install Ubuntu ver. 8.10 and running into some issues with the graphics card, I decided to give the original Windows 7 OS a go and used the Re-installation DVD that came with my laptop to reformat the HD. The first sign of trouble was when I noticed that my wireless device was not being recognized by the newly-installed OS. After searching through a list of my devices and drives, I have discovered several, including the Network Controller, that report as being 'not installed'. However, my computer, including internet connection.etc. appears to be operating properly. My real question boils down to this: When I attempt to download Drivers from the Dell website's Drivers & Downloads page, how do I know what I should be installing and not installing? Obviously I shouldn't be installing everything that has 'recommended' next to it, but none of the programs listed seem to fit what I'm apparently missing. Also, what in the world can I do about my Network Controller? Allowing Dell to try to find an update for the driver on its own has been unsuccessful. Besides the Network Controller, the other drivers that seem to be problematic include: Standard PS/2 Keyboard, Intel ICH9 Family SMBus Controller - 2930, Mobile Intel 4 Series Chipset PCI Express Root Port - 2A41, Mobile Intel 4 Series Processor to DRAM Controller - 2A40, and Standard AHCI 1.0 Serial ATA Controller.   ETC: Downloading and installing the driver for my wireless card (Wireless WLAN 1520 Half MiniCard) did absolutely nothing - it never even prompted me to restart the computer.
Missing/uninstalled drivers following use of OS Re-Installation DVD