Win7 should automatically install the drivers it needs for the hardware in your laptop. If it does not, go to www.support.dell.com and enter the service tag of your computer. Then to the drivers page for your computer. Download the drivers needed for your computer and install them.
An alternative is to open Device manager, find the particular hardware items in the list. right-click on each one of them and choose update driver.
The problem may not be your computer but your router/modem?