Sorry I did not see this thread. There are several password resetting programmes you could have used.
If you have a new Dell PC you should have received a companion Dell Resource Disk (CD) that contains all the necessary video, Audio ETC drivers. Just place the CD in the drive. It should run and offer to install the Dell Resource. This will install and will then detect the model and then in a sort of explorer screen will display a list of the hardware found on the machine. There will be an install button under each item. The process is very well explained and should take just 10 - 20 minutes. It WILL want you to restart the machine between each installation of a driver. Do NOT ignore this, just restart the PC each time!
If you don't have or can't find the Dell Resource disk the drivers are all available for download at the Dell website. Just type in the Service Tag number of the PC and it will automatically select the correct versions.
Chris