On a laptop, attempting to boot up resulted in a brief error and return to the reboot sequence. Selecting safe boot, did not help nor did attempting to go back to a previously good boot.
At some point, I saw the inpage error message.
The problem was that somehow, the C: drive got corrupted. The D: drive (partition on the same physical drive) is used as a GateWay recovery partition and it was OK, so I know the drive itself was OK; just the C: partiton was messed up.
I did not want to re-install using the D: drive (by hitting F11 at boot)....
My Brother 420CN printer said Low Ink or No Ink on some cartridges and I tried just pulling them out and putting them back in since they all still had at least 1/2 a tank of ink.
After closing the cover, the LCD showed No Cartridge instead of asking me which carts were replaced. I couldn't get rid of the message except by unplugging the printer but then it went back to the No/Low errors.
The solution is to:
Unplug printer
Open and remove all carts
Plug in with cover...