Turn the ADIRU off, wait a few seconds, then turn it back on.

Using the attached image as a guide, on the POS INIT page of the CDU, a series of empty blocks should appear (orange square) next to LSK5R (yellow square).
To allign, click on LSK4R (green square), to "copy" the coordinates there (the co-odinates should appear on the scratchpad (blue square)), then click on LSK5R to "paste" the co-ordinates into the blank blocks. After a few minutes it should align.
As a general rule, do not start the engines, or move the 777 until after the ADIRU is aligned.

Note. Alignment will take a few minutes unless you go to CDU > MENU > SETUP > Click on LSK4L beside FAST ALIGN, which will immediately align the ADIRU. ;)

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