My main Windows install is currently inaccessible due to a hardware incompatibility with my current drivers. I have a secondary hard drive with another Windows install on it; this drive can boot successfully. Is it possible for me to install drivers to the Windows installation which isn't currently running? More importantly, is it possible to do this without the Windows install DVD?
You may be able to place drive files and installers in place on the disk and remove faulty driver files, forcing the system to reconfigure those devices. But you'll have difficulty mounting the registry from an unloaded OS, which contains critical functions relating to the drivers.
Removing the faulty driver files should be sufficient though, unless the OS itself is messed up and needs repair.
To clarify: I do not mean try and place new driver files into installed locations on the drive. I mean simply placing the driver packages/installer/files to an accessible location on the drive.
Once you've removed the old/bad driver file, the OS should ask you for new drivers, at which point you'd be able to go through the normal installation process for each driver. Because the OS places driver information in multiple locations that are difficult to modify in an unbooted OS, the best and safest way to get new drivers into place correctly is to force the system to look for new drivers and having the correct drivers ready makes this process less painful.