System32DRIVERSisapnp.sys is corrupted/ missing in Dell Laptop

When I tried to start up my Dell laptop, I am receiving an error message caused by installation of the new hardware/software. When troubleshooting windows in Safe mode, it keeps saying that the System32DRIVERSisapnp.sys is corrupted/ missing. Also, I do not have the installation CD to try reinstalling Windows. How can I resolve the issue? Please help.
