You can "install" and "uninstall" core drivers by just copying the relevant files and updating the registry settings (this is how drivers are installed by any other program). But this method is possibly prone to errors as if it is unlikely that it is just your hard drive drivers.
To corrupt those drivers requires writes into the Windows System directory and Registry keys (HKLM\system\currentcontrolset). Even if you somehow manage to mess with the registry keys, Windows keeps a backup copy of the registry keys. Considering how both failed, I'd be suspicious if only those were the issues needed to be fixed.
My guess is something else got worked over as well and I'd advise a more complete solution.
Use the SFC /scannow command first. If not, I'd look at reinstalling Windows. You don't have to reformat the harddrive, Windows will move all your old data to a folder named Windows.old.