Local Area Connection won't enable

Hey Guys
I'm having a Very Serious problem with my network since my anti-virus found that ndis.sys file was infected with virus! I deleted the infected file from my computer and copied it to the same location from the Windows Xp CD.
But still i face the same problem! The local area connection is disabled and i am unable to enable it. When i double click on the connection to enable it, it says "Enabling..." for a few seconds and says "Connection Failed!"
What do i do to fix this? please help me!

Try to Reinstall the drivers, that may fix your problem!

ndis.sys is a wrapper driver, a driver that translates your driver to your OS (driver wrappers are needed when the driver being used is not known by the OS by default). So, as Steve suggested, reinstalling the driver should fix the problem. Completely uninstall the device, and then let Windows find it on reboot. Then install it from the manufacturer's disc. All the best!