The drivers should be built into the kernel already if you’re using onboard Intel graphics.
The system might be loading the wrong driver module for its chipset—unlikely, but possible. The correct driver for your chipset should be i915. You can check by running lspci -v and finding the Kernel driver in use line for your video card. (There may be other ways of checking as well.)
Personally, if this computer will normally be operating in headless mode, I’d just ignore this altogether, disconnect the monitor, and administer it via SSH from a machine not having these issues.