If you receive the error message “The operating system is not presently configured to run this application” when opening Office and other applications, the ...
If you have recently seen an error message A component of the operating system has expired with error code 0xc0000605, here are some possible solutions that may help ...
EDIT: It did - changing that setting back to "AHCI" resulted in a, "This operating system failed to start", message when I tried to boot XP. Changing the BIOS back to the "IDE" setting didn't fix that ...