Dell dimension 1100 driver

Go to the Dell website, look up your computer by model number. Download the driver(s), save to the desktop.
Turn off the antivirus and firewall, install the driver(s), restart the computer, turn the antivirus and firewall back on.
There are several drivers for that computer, about 8 in all. You can install all of them as above. There is a special order for installing the drivers in a Dell computer. Read the directions for installing on the Dell website.